keys = returnedItem.keySet();
System.out.println("Amazon DynamoDB table attributes: \n");
for (String key1 : keys) {
System.out.format("%s: %s\n", key1, returnedItem.get(key1).toString());
}
} else {
System.out.format("No item found with the key %s!\n", "year");
}
} catch (DynamoDbException e) {
System.err.println(e.getMessage());
System.exit(1);
}
}
```
完整示例。
```
/**
* Before running this Java V2 code example, set up your development
* environment, including your credentials.
*
* For more information, see the following documentation topic:
*
* https://docs.aws.amazon.com/sdk-for-java/latest/developer-guide/get-started.html
*
* This Java example performs these tasks:
*
* 1. Creates the Amazon DynamoDB Movie table with partition and sort key.
* 2. Puts data into the Amazon DynamoDB table from a JSON document using the
* Enhanced client.
* 3. Gets data from the Movie table.
* 4. Adds a new item.
* 5. Updates an item.
* 6. Uses a Scan to query items using the Enhanced client.
* 7. Queries all items where the year is 2013 using the Enhanced Client.
* 8. Deletes the table.
*/
public class Scenario {
public static final String DASHES = new String(new char[80]).replace("\0", "-");
public static void main(String[] args) throws IOException {
String tableName = "Movies";
String fileName = "../../../resources/sample_files/movies.json";
Region region = Region.US_EAST_1;
DynamoDbClient ddb = DynamoDbClient.builder()
.region(region)
.build();
System.out.println(DASHES);
System.out.println("Welcome to the Amazon DynamoDB example scenario.");
System.out.println(DASHES);
System.out.println(DASHES);
System.out.println(
"1. Creating an Amazon DynamoDB table named Movies with a key named year and a sort key named title.");
createTable(ddb, tableName);
System.out.println(DASHES);
System.out.println(DASHES);
System.out.println("2. Loading data into the Amazon DynamoDB table.");
loadData(ddb, tableName, fileName);
System.out.println(DASHES);
System.out.println(DASHES);
System.out.println("3. Getting data from the Movie table.");
getItem(ddb);
System.out.println(DASHES);
System.out.println(DASHES);
System.out.println("4. Putting a record into the Amazon DynamoDB table.");
putRecord(ddb);
System.out.println(DASHES);
System.out.println(DASHES);
System.out.println("5. Updating a record.");
updateTableItem(ddb, tableName);
System.out.println(DASHES);
System.out.println(DASHES);
System.out.println("6. Scanning the Amazon DynamoDB table.");
scanMovies(ddb, tableName);
System.out.println(DASHES);
System.out.println(DASHES);
System.out.println("7. Querying the Movies released in 2013.");
queryTable(ddb);
System.out.println(DASHES);
System.out.println(DASHES);
System.out.println("8. Deleting the Amazon DynamoDB table.");
deleteDynamoDBTable(ddb, tableName);
System.out.println(DASHES);
ddb.close();
}
// Create a table with a Sort key.
public static void createTable(DynamoDbClient ddb, String tableName) {
DynamoDbWaiter dbWaiter = ddb.waiter();
ArrayList attributeDefinitions = new ArrayList<>();
// Define attributes.
attributeDefinitions.add(AttributeDefinition.builder()
.attributeName("year")
.attributeType("N")
.build());
attributeDefinitions.add(AttributeDefinition.builder()
.attributeName("title")
.attributeType("S")
.build());
ArrayList tableKey = new ArrayList<>();
KeySchemaElement key = KeySchemaElement.builder()
.attributeName("year")
.keyType(KeyType.HASH)
.build();
KeySchemaElement key2 = KeySchemaElement.builder()
.attributeName("title")
.keyType(KeyType.RANGE)
.build();
// Add KeySchemaElement objects to the list.
tableKey.add(key);
tableKey.add(key2);
CreateTableRequest request = CreateTableRequest.builder()
.keySchema(tableKey)
.billingMode(BillingMode.PAY_PER_REQUEST) // DynamoDB automatically scales based on traffic.
.attributeDefinitions(attributeDefinitions)
.tableName(tableName)
.build();
try {
CreateTableResponse response = ddb.createTable(request);
DescribeTableRequest tableRequest = DescribeTableRequest.builder()
.tableName(tableName)
.build();
// Wait until the Amazon DynamoDB table is created.
WaiterResponse waiterResponse = dbWaiter.waitUntilTableExists(tableRequest);
waiterResponse.matched().response().ifPresent(System.out::println);
String newTable = response.tableDescription().tableName();
System.out.println("The " + newTable + " was successfully created.");
} catch (DynamoDbException e) {
System.err.println(e.getMessage());
System.exit(1);
}
}
// Query the table.
public static void queryTable(DynamoDbClient ddb) {
try {
DynamoDbEnhancedClient enhancedClient = DynamoDbEnhancedClient.builder()
.dynamoDbClient(ddb)
.build();
DynamoDbTable custTable = enhancedClient.table("Movies", TableSchema.fromBean(Movies.class));
QueryConditional queryConditional = QueryConditional
.keyEqualTo(Key.builder()
.partitionValue(2013)
.build());
// Get items in the table and write out the ID value.
Iterator results = custTable.query(queryConditional).items().iterator();
String result = "";
while (results.hasNext()) {
Movies rec = results.next();
System.out.println("The title of the movie is " + rec.getTitle());
System.out.println("The movie information is " + rec.getInfo());
}
} catch (DynamoDbException e) {
System.err.println(e.getMessage());
System.exit(1);
}
}
// Scan the table.
public static void scanMovies(DynamoDbClient ddb, String tableName) {
System.out.println("******* Scanning all movies.\n");
try {
DynamoDbEnhancedClient enhancedClient = DynamoDbEnhancedClient.builder()
.dynamoDbClient(ddb)
.build();
DynamoDbTable custTable = enhancedClient.table("Movies", TableSchema.fromBean(Movies.class));
Iterator results = custTable.scan().items().iterator();
while (results.hasNext()) {
Movies rec = results.next();
System.out.println("The movie title is " + rec.getTitle());
System.out.println("The movie year is " + rec.getYear());
}
} catch (DynamoDbException e) {
System.err.println(e.getMessage());
System.exit(1);
}
}
// Load data into the table.
public static void loadData(DynamoDbClient ddb, String tableName, String fileName) throws IOException {
DynamoDbEnhancedClient enhancedClient = DynamoDbEnhancedClient.builder()
.dynamoDbClient(ddb)
.build();
DynamoDbTable mappedTable = enhancedClient.table("Movies", TableSchema.fromBean(Movies.class));
JsonParser parser = new JsonFactory().createParser(new File(fileName));
com.fasterxml.jackson.databind.JsonNode rootNode = new ObjectMapper().readTree(parser);
Iterator iter = rootNode.iterator();
ObjectNode currentNode;
int t = 0;
while (iter.hasNext()) {
// Only add 200 Movies to the table.
if (t == 200)
break;
currentNode = (ObjectNode) iter.next();
int year = currentNode.path("year").asInt();
String title = currentNode.path("title").asText();
String info = currentNode.path("info").toString();
Movies movies = new Movies();
movies.setYear(year);
movies.setTitle(title);
movies.setInfo(info);
// Put the data into the Amazon DynamoDB Movie table.
mappedTable.putItem(movies);
t++;
}
}
// Update the record to include show only directors.
public static void updateTableItem(DynamoDbClient ddb, String tableName) {
HashMap itemKey = new HashMap<>();
itemKey.put("year", AttributeValue.builder().n("1933").build());
itemKey.put("title", AttributeValue.builder().s("King Kong").build());
HashMap updatedValues = new HashMap<>();
updatedValues.put("info", AttributeValueUpdate.builder()
.value(AttributeValue.builder().s("{\"directors\":[\"Merian C. Cooper\",\"Ernest B. Schoedsack\"]")
.build())
.action(AttributeAction.PUT)
.build());
UpdateItemRequest request = UpdateItemRequest.builder()
.tableName(tableName)
.key(itemKey)
.attributeUpdates(updatedValues)
.build();
try {
ddb.updateItem(request);
} catch (ResourceNotFoundException e) {
System.err.println(e.getMessage());
System.exit(1);
} catch (DynamoDbException e) {
System.err.println(e.getMessage());
System.exit(1);
}
System.out.println("Item was updated!");
}
public static void deleteDynamoDBTable(DynamoDbClient ddb, String tableName) {
DeleteTableRequest request = DeleteTableRequest.builder()
.tableName(tableName)
.build();
try {
ddb.deleteTable(request);
} catch (DynamoDbException e) {
System.err.println(e.getMessage());
System.exit(1);
}
System.out.println(tableName + " was successfully deleted!");
}
public static void putRecord(DynamoDbClient ddb) {
try {
DynamoDbEnhancedClient enhancedClient = DynamoDbEnhancedClient.builder()
.dynamoDbClient(ddb)
.build();
DynamoDbTable table = enhancedClient.table("Movies", TableSchema.fromBean(Movies.class));
// Populate the Table.
Movies record = new Movies();
record.setYear(2020);
record.setTitle("My Movie2");
record.setInfo("no info");
table.putItem(record);
} catch (DynamoDbException e) {
System.err.println(e.getMessage());
System.exit(1);
}
System.out.println("Added a new movie to the table.");
}
public static void getItem(DynamoDbClient ddb) {
HashMap keyToGet = new HashMap<>();
keyToGet.put("year", AttributeValue.builder()
.n("1933")
.build());
keyToGet.put("title", AttributeValue.builder()
.s("King Kong")
.build());
GetItemRequest request = GetItemRequest.builder()
.key(keyToGet)
.tableName("Movies")
.build();
try {
Map returnedItem = ddb.getItem(request).item();
if (returnedItem != null) {
Set keys = returnedItem.keySet();
System.out.println("Amazon DynamoDB table attributes: \n");
for (String key1 : keys) {
System.out.format("%s: %s\n", key1, returnedItem.get(key1).toString());
}
} else {
System.out.format("No item found with the key %s!\n", "year");
}
} catch (DynamoDbException e) {
System.err.println(e.getMessage());
System.exit(1);
}
}
}
```
+ 有关 API 详细信息，请参阅《AWS SDK for Java 2.x API Reference》**中的以下主题。
+ [BatchWriteItem](https://docs.aws.amazon.com/goto/SdkForJavaV2/dynamodb-2012-08-10/BatchWriteItem)
+ [CreateTable](https://docs.aws.amazon.com/goto/SdkForJavaV2/dynamodb-2012-08-10/CreateTable)
+ [DeleteItem](https://docs.aws.amazon.com/goto/SdkForJavaV2/dynamodb-2012-08-10/DeleteItem)
+ [DeleteTable](https://docs.aws.amazon.com/goto/SdkForJavaV2/dynamodb-2012-08-10/DeleteTable)
+ [DescribeTable](https://docs.aws.amazon.com/goto/SdkForJavaV2/dynamodb-2012-08-10/DescribeTable)
+ [GetItem](https://docs.aws.amazon.com/goto/SdkForJavaV2/dynamodb-2012-08-10/GetItem)
+ [PutItem](https://docs.aws.amazon.com/goto/SdkForJavaV2/dynamodb-2012-08-10/PutItem)
+ [Query](https://docs.aws.amazon.com/goto/SdkForJavaV2/dynamodb-2012-08-10/Query)
+ [Scan](https://docs.aws.amazon.com/goto/SdkForJavaV2/dynamodb-2012-08-10/Scan)
+ [UpdateItem](https://docs.aws.amazon.com/goto/SdkForJavaV2/dynamodb-2012-08-10/UpdateItem)
------
#### [ JavaScript ]
**SDK for JavaScript (v3)**
查看 GitHub，了解更多信息。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javascriptv3/example_code/dynamodb#code-examples) 中查找完整示例，了解如何进行设置和运行。
```
import { readFileSync } from "node:fs";
import {
BillingMode,
CreateTableCommand,
DeleteTableCommand,
DynamoDBClient,
waitUntilTableExists,
} from "@aws-sdk/client-dynamodb";
/**
* This module is a convenience library. It abstracts Amazon DynamoDB's data type
* descriptors (such as S, N, B, and BOOL) by marshalling JavaScript objects into
* AttributeValue shapes.
*/
import {
BatchWriteCommand,
DeleteCommand,
DynamoDBDocumentClient,
GetCommand,
PutCommand,
UpdateCommand,
paginateQuery,
paginateScan,
} from "@aws-sdk/lib-dynamodb";
// These modules are local to our GitHub repository. We recommend cloning
// the project from GitHub if you want to run this example.
// For more information, see https://github.com/awsdocs/aws-doc-sdk-examples.
import { getUniqueName } from "@aws-doc-sdk-examples/lib/utils/util-string.js";
import { dirnameFromMetaUrl } from "@aws-doc-sdk-examples/lib/utils/util-fs.js";
import { chunkArray } from "@aws-doc-sdk-examples/lib/utils/util-array.js";
const dirname = dirnameFromMetaUrl(import.meta.url);
const tableName = getUniqueName("Movies");
const client = new DynamoDBClient({});
const docClient = DynamoDBDocumentClient.from(client);
const log = (msg) => console.log(`[SCENARIO] ${msg}`);
export const main = async () => {
/**
* Create a table.
*/
const createTableCommand = new CreateTableCommand({
TableName: tableName,
// This example performs a large write to the database.
// Set the billing mode to PAY_PER_REQUEST to
// avoid throttling the large write.
BillingMode: BillingMode.PAY_PER_REQUEST,
// Define the attributes that are necessary for the key schema.
AttributeDefinitions: [
{
AttributeName: "year",
// 'N' is a data type descriptor that represents a number type.
// For a list of all data type descriptors, see the following link.
// https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/Programming.LowLevelAPI.html#Programming.LowLevelAPI.DataTypeDescriptors
AttributeType: "N",
},
{ AttributeName: "title", AttributeType: "S" },
],
// The KeySchema defines the primary key. The primary key can be
// a partition key, or a combination of a partition key and a sort key.
// Key schema design is important. For more info, see
// https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/best-practices.html
KeySchema: [
// The way your data is accessed determines how you structure your keys.
// The movies table will be queried for movies by year. It makes sense
// to make year our partition (HASH) key.
{ AttributeName: "year", KeyType: "HASH" },
{ AttributeName: "title", KeyType: "RANGE" },
],
});
log("Creating a table.");
const createTableResponse = await client.send(createTableCommand);
log(`Table created: ${JSON.stringify(createTableResponse.TableDescription)}`);
// This polls with DescribeTableCommand until the requested table is 'ACTIVE'.
// You can't write to a table before it's active.
log("Waiting for the table to be active.");
await waitUntilTableExists({ client }, { TableName: tableName });
log("Table active.");
/**
* Add a movie to the table.
*/
log("Adding a single movie to the table.");
// PutCommand is the first example usage of 'lib-dynamodb'.
const putCommand = new PutCommand({
TableName: tableName,
Item: {
// In 'client-dynamodb', the AttributeValue would be required (`year: { N: 1981 }`)
// 'lib-dynamodb' simplifies the usage ( `year: 1981` )
year: 1981,
// The preceding KeySchema defines 'title' as our sort (RANGE) key, so 'title'
// is required.
title: "The Evil Dead",
// Every other attribute is optional.
info: {
genres: ["Horror"],
},
},
});
await docClient.send(putCommand);
log("The movie was added.");
/**
* Get a movie from the table.
*/
log("Getting a single movie from the table.");
const getCommand = new GetCommand({
TableName: tableName,
// Requires the complete primary key. For the movies table, the primary key
// is only the id (partition key).
Key: {
year: 1981,
title: "The Evil Dead",
},
// Set this to make sure that recent writes are reflected.
// For more information, see https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/HowItWorks.ReadConsistency.html.
ConsistentRead: true,
});
const getResponse = await docClient.send(getCommand);
log(`Got the movie: ${JSON.stringify(getResponse.Item)}`);
/**
* Update a movie in the table.
*/
log("Updating a single movie in the table.");
const updateCommand = new UpdateCommand({
TableName: tableName,
Key: { year: 1981, title: "The Evil Dead" },
// This update expression appends "Comedy" to the list of genres.
// For more information on update expressions, see
// https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/Expressions.UpdateExpressions.html
UpdateExpression: "set #i.#g = list_append(#i.#g, :vals)",
ExpressionAttributeNames: { "#i": "info", "#g": "genres" },
ExpressionAttributeValues: {
":vals": ["Comedy"],
},
ReturnValues: "ALL_NEW",
});
const updateResponse = await docClient.send(updateCommand);
log(`Movie updated: ${JSON.stringify(updateResponse.Attributes)}`);
/**
* Delete a movie from the table.
*/
log("Deleting a single movie from the table.");
const deleteCommand = new DeleteCommand({
TableName: tableName,
Key: { year: 1981, title: "The Evil Dead" },
});
await docClient.send(deleteCommand);
log("Movie deleted.");
/**
* Upload a batch of movies.
*/
log("Adding movies from local JSON file.");
const file = readFileSync(
`${dirname}../../../../resources/sample_files/movies.json`,
);
const movies = JSON.parse(file.toString());
// chunkArray is a local convenience function. It takes an array and returns
// a generator function. The generator function yields every N items.
const movieChunks = chunkArray(movies, 25);
// For every chunk of 25 movies, make one BatchWrite request.
for (const chunk of movieChunks) {
const putRequests = chunk.map((movie) => ({
PutRequest: {
Item: movie,
},
}));
const command = new BatchWriteCommand({
RequestItems: {
[tableName]: putRequests,
},
});
await docClient.send(command);
}
log("Movies added.");
/**
* Query for movies by year.
*/
log("Querying for all movies from 1981.");
const paginatedQuery = paginateQuery(
{ client: docClient },
{
TableName: tableName,
//For more information about query expressions, see
// https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/Query.html#Query.KeyConditionExpressions
KeyConditionExpression: "#y = :y",
// 'year' is a reserved word in DynamoDB. Indicate that it's an attribute
// name by using an expression attribute name.
ExpressionAttributeNames: { "#y": "year" },
ExpressionAttributeValues: { ":y": 1981 },
ConsistentRead: true,
},
);
/**
* @type { Record[] };
*/
const movies1981 = [];
for await (const page of paginatedQuery) {
movies1981.push(...page.Items);
}
log(`Movies: ${movies1981.map((m) => m.title).join(", ")}`);
/**
* Scan the table for movies between 1980 and 1990.
*/
log("Scan for movies released between 1980 and 1990");
// A 'Scan' operation always reads every item in the table. If your design requires
// the use of 'Scan', consider indexing your table or changing your design.
// https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/bp-query-scan.html
const paginatedScan = paginateScan(
{ client: docClient },
{
TableName: tableName,
// Scan uses a filter expression instead of a key condition expression. Scan will
// read the entire table and then apply the filter.
FilterExpression: "#y between :y1 and :y2",
ExpressionAttributeNames: { "#y": "year" },
ExpressionAttributeValues: { ":y1": 1980, ":y2": 1990 },
ConsistentRead: true,
},
);
/**
* @type { Record[] };
*/
const movies1980to1990 = [];
for await (const page of paginatedScan) {
movies1980to1990.push(...page.Items);
}
log(
`Movies: ${movies1980to1990
.map((m) => `${m.title} (${m.year})`)
.join(", ")}`,
);
/**
* Delete the table.
*/
const deleteTableCommand = new DeleteTableCommand({ TableName: tableName });
log(`Deleting table ${tableName}.`);
await client.send(deleteTableCommand);
log("Table deleted.");
};
```
+ 有关 API 详细信息，请参阅《适用于 JavaScript 的 AWS SDK API Reference》**中的以下主题。
+ [BatchWriteItem](https://docs.aws.amazon.com/AWSJavaScriptSDK/v3/latest/client/dynamodb/command/BatchWriteItemCommand)
+ [CreateTable](https://docs.aws.amazon.com/AWSJavaScriptSDK/v3/latest/client/dynamodb/command/CreateTableCommand)
+ [DeleteItem](https://docs.aws.amazon.com/AWSJavaScriptSDK/v3/latest/client/dynamodb/command/DeleteItemCommand)
+ [DeleteTable](https://docs.aws.amazon.com/AWSJavaScriptSDK/v3/latest/client/dynamodb/command/DeleteTableCommand)
+ [DescribeTable](https://docs.aws.amazon.com/AWSJavaScriptSDK/v3/latest/client/dynamodb/command/DescribeTableCommand)
+ [GetItem](https://docs.aws.amazon.com/AWSJavaScriptSDK/v3/latest/client/dynamodb/command/GetItemCommand)
+ [PutItem](https://docs.aws.amazon.com/AWSJavaScriptSDK/v3/latest/client/dynamodb/command/PutItemCommand)
+ [Query](https://docs.aws.amazon.com/AWSJavaScriptSDK/v3/latest/client/dynamodb/command/QueryCommand)
+ [Scan](https://docs.aws.amazon.com/AWSJavaScriptSDK/v3/latest/client/dynamodb/command/ScanCommand)
+ [UpdateItem](https://docs.aws.amazon.com/AWSJavaScriptSDK/v3/latest/client/dynamodb/command/UpdateItemCommand)
------
#### [ Kotlin ]
**SDK for Kotlin**
查看 GitHub，了解更多信息。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/kotlin/services/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
创建 DynamoDB 表。
```
suspend fun createScenarioTable(
tableNameVal: String,
key: String,
) {
val attDef =
AttributeDefinition {
attributeName = key
attributeType = ScalarAttributeType.N
}
val attDef1 =
AttributeDefinition {
attributeName = "title"
attributeType = ScalarAttributeType.S
}
val keySchemaVal =
KeySchemaElement {
attributeName = key
keyType = KeyType.Hash
}
val keySchemaVal1 =
KeySchemaElement {
attributeName = "title"
keyType = KeyType.Range
}
val request =
CreateTableRequest {
attributeDefinitions = listOf(attDef, attDef1)
keySchema = listOf(keySchemaVal, keySchemaVal1)
billingMode = BillingMode.PayPerRequest
tableName = tableNameVal
}
DynamoDbClient.fromEnvironment { region = "us-east-1" }.use { ddb ->
val response = ddb.createTable(request)
ddb.waitUntilTableExists {
// suspend call
tableName = tableNameVal
}
println("The table was successfully created ${response.tableDescription?.tableArn}")
}
}
```
创建帮助函数以下载并提取示例 JSON 文件。
```
// Load data into the table.
suspend fun loadData(
tableName: String,
fileName: String,
) {
val parser = JsonFactory().createParser(File(fileName))
val rootNode = ObjectMapper().readTree(parser)
val iter: Iterator = rootNode.iterator()
var currentNode: ObjectNode
var t = 0
while (iter.hasNext()) {
if (t == 50) {
break
}
currentNode = iter.next() as ObjectNode
val year = currentNode.path("year").asInt()
val title = currentNode.path("title").asText()
val info = currentNode.path("info").toString()
putMovie(tableName, year, title, info)
t++
}
}
suspend fun putMovie(
tableNameVal: String,
year: Int,
title: String,
info: String,
) {
val itemValues = mutableMapOf()
val strVal = year.toString()
// Add all content to the table.
itemValues["year"] = AttributeValue.N(strVal)
itemValues["title"] = AttributeValue.S(title)
itemValues["info"] = AttributeValue.S(info)
val request =
PutItemRequest {
tableName = tableNameVal
item = itemValues
}
DynamoDbClient.fromEnvironment { region = "us-east-1" }.use { ddb ->
ddb.putItem(request)
println("Added $title to the Movie table.")
}
}
```
从表中获取项目。
```
suspend fun getMovie(
tableNameVal: String,
keyName: String,
keyVal: String,
) {
val keyToGet = mutableMapOf()
keyToGet[keyName] = AttributeValue.N(keyVal)
keyToGet["title"] = AttributeValue.S("King Kong")
val request =
GetItemRequest {
key = keyToGet
tableName = tableNameVal
}
DynamoDbClient.fromEnvironment { region = "us-east-1" }.use { ddb ->
val returnedItem = ddb.getItem(request)
val numbersMap = returnedItem.item
numbersMap?.forEach { key1 ->
println(key1.key)
println(key1.value)
}
}
}
```
完整示例。
```
suspend fun main() {
val tableName = "Movies"
val fileName = "../../../resources/sample_files/movies.json"
val partitionAlias = "#a"
println("Creating an Amazon DynamoDB table named Movies with a key named id and a sort key named title.")
createScenarioTable(tableName, "year")
loadData(tableName, fileName)
getMovie(tableName, "year", "1933")
scanMovies(tableName)
val count = queryMovieTable(tableName, "year", partitionAlias)
println("There are $count Movies released in 2013.")
deletIssuesTable(tableName)
}
suspend fun createScenarioTable(
tableNameVal: String,
key: String,
) {
val attDef =
AttributeDefinition {
attributeName = key
attributeType = ScalarAttributeType.N
}
val attDef1 =
AttributeDefinition {
attributeName = "title"
attributeType = ScalarAttributeType.S
}
val keySchemaVal =
KeySchemaElement {
attributeName = key
keyType = KeyType.Hash
}
val keySchemaVal1 =
KeySchemaElement {
attributeName = "title"
keyType = KeyType.Range
}
val request =
CreateTableRequest {
attributeDefinitions = listOf(attDef, attDef1)
keySchema = listOf(keySchemaVal, keySchemaVal1)
billingMode = BillingMode.PayPerRequest
tableName = tableNameVal
}
DynamoDbClient.fromEnvironment { region = "us-east-1" }.use { ddb ->
val response = ddb.createTable(request)
ddb.waitUntilTableExists {
// suspend call
tableName = tableNameVal
}
println("The table was successfully created ${response.tableDescription?.tableArn}")
}
}
// Load data into the table.
suspend fun loadData(
tableName: String,
fileName: String,
) {
val parser = JsonFactory().createParser(File(fileName))
val rootNode = ObjectMapper().readTree(parser)
val iter: Iterator = rootNode.iterator()
var currentNode: ObjectNode
var t = 0
while (iter.hasNext()) {
if (t == 50) {
break
}
currentNode = iter.next() as ObjectNode
val year = currentNode.path("year").asInt()
val title = currentNode.path("title").asText()
val info = currentNode.path("info").toString()
putMovie(tableName, year, title, info)
t++
}
}
suspend fun putMovie(
tableNameVal: String,
year: Int,
title: String,
info: String,
) {
val itemValues = mutableMapOf()
val strVal = year.toString()
// Add all content to the table.
itemValues["year"] = AttributeValue.N(strVal)
itemValues["title"] = AttributeValue.S(title)
itemValues["info"] = AttributeValue.S(info)
val request =
PutItemRequest {
tableName = tableNameVal
item = itemValues
}
DynamoDbClient.fromEnvironment { region = "us-east-1" }.use { ddb ->
ddb.putItem(request)
println("Added $title to the Movie table.")
}
}
suspend fun getMovie(
tableNameVal: String,
keyName: String,
keyVal: String,
) {
val keyToGet = mutableMapOf()
keyToGet[keyName] = AttributeValue.N(keyVal)
keyToGet["title"] = AttributeValue.S("King Kong")
val request =
GetItemRequest {
key = keyToGet
tableName = tableNameVal
}
DynamoDbClient.fromEnvironment { region = "us-east-1" }.use { ddb ->
val returnedItem = ddb.getItem(request)
val numbersMap = returnedItem.item
numbersMap?.forEach { key1 ->
println(key1.key)
println(key1.value)
}
}
}
suspend fun deletIssuesTable(tableNameVal: String) {
val request =
DeleteTableRequest {
tableName = tableNameVal
}
DynamoDbClient.fromEnvironment { region = "us-east-1" }.use { ddb ->
ddb.deleteTable(request)
println("$tableNameVal was deleted")
}
}
suspend fun queryMovieTable(
tableNameVal: String,
partitionKeyName: String,
partitionAlias: String,
): Int {
val attrNameAlias = mutableMapOf()
attrNameAlias[partitionAlias] = "year"
// Set up mapping of the partition name with the value.
val attrValues = mutableMapOf()
attrValues[":$partitionKeyName"] = AttributeValue.N("2013")
val request =
QueryRequest {
tableName = tableNameVal
keyConditionExpression = "$partitionAlias = :$partitionKeyName"
expressionAttributeNames = attrNameAlias
this.expressionAttributeValues = attrValues
}
DynamoDbClient.fromEnvironment { region = "us-east-1" }.use { ddb ->
val response = ddb.query(request)
return response.count
}
}
suspend fun scanMovies(tableNameVal: String) {
val request =
ScanRequest {
tableName = tableNameVal
}
DynamoDbClient.fromEnvironment { region = "us-east-1" }.use { ddb ->
val response = ddb.scan(request)
response.items?.forEach { item ->
item.keys.forEach { key ->
println("The key name is $key\n")
println("The value is ${item[key]}")
}
}
}
}
```
+ 有关 API 详细信息，请参阅《AWS SDK for Kotlin API Reference》**中的以下主题。
+ [BatchWriteItem](https://sdk.amazonaws.com/kotlin/api/latest/index.html)
+ [CreateTable](https://sdk.amazonaws.com/kotlin/api/latest/index.html)
+ [DeleteItem](https://sdk.amazonaws.com/kotlin/api/latest/index.html)
+ [DeleteTable](https://sdk.amazonaws.com/kotlin/api/latest/index.html)
+ [DescribeTable](https://sdk.amazonaws.com/kotlin/api/latest/index.html)
+ [GetItem](https://sdk.amazonaws.com/kotlin/api/latest/index.html)
+ [PutItem](https://sdk.amazonaws.com/kotlin/api/latest/index.html)
+ [Query](https://sdk.amazonaws.com/kotlin/api/latest/index.html)
+ [Scan](https://sdk.amazonaws.com/kotlin/api/latest/index.html)
+ [UpdateItem](https://sdk.amazonaws.com/kotlin/api/latest/index.html)
------
#### [ PHP ]
**适用于 PHP 的 SDK**
查看 GitHub，了解更多信息。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/php/example_code/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
由于此示例使用支持文件，因此请务必[阅读指南](https://github.com/awsdocs/aws-doc-sdk-examples/blob/main/php/README.md#prerequisites)（位于 PHP 示例 README.md 文件中）。
```
namespace DynamoDb\Basics;
use Aws\DynamoDb\Marshaler;
use DynamoDb;
use DynamoDb\DynamoDBAttribute;
use DynamoDb\DynamoDBService;
use function AwsUtilities\loadMovieData;
use function AwsUtilities\testable_readline;
class GettingStartedWithDynamoDB
{
public function run()
{
echo("\n");
echo("--------------------------------------\n");
print("Welcome to the Amazon DynamoDB getting started demo using PHP!\n");
echo("--------------------------------------\n");
$uuid = uniqid();
$service = new DynamoDBService();
$tableName = "ddb_demo_table_$uuid";
$service->createTable(
$tableName,
[
new DynamoDBAttribute('year', 'N', 'HASH'),
new DynamoDBAttribute('title', 'S', 'RANGE')
]
);
echo "Waiting for table...";
$service->dynamoDbClient->waitUntil("TableExists", ['TableName' => $tableName]);
echo "table $tableName found!\n";
echo "What's the name of the last movie you watched?\n";
while (empty($movieName)) {
$movieName = testable_readline("Movie name: ");
}
echo "And what year was it released?\n";
$movieYear = "year";
while (!is_numeric($movieYear) || intval($movieYear) != $movieYear) {
$movieYear = testable_readline("Year released: ");
}
$service->putItem([
'Item' => [
'year' => [
'N' => "$movieYear",
],
'title' => [
'S' => $movieName,
],
],
'TableName' => $tableName,
]);
echo "How would you rate the movie from 1-10?\n";
$rating = 0;
while (!is_numeric($rating) || intval($rating) != $rating || $rating < 1 || $rating > 10) {
$rating = testable_readline("Rating (1-10): ");
}
echo "What was the movie about?\n";
while (empty($plot)) {
$plot = testable_readline("Plot summary: ");
}
$key = [
'Item' => [
'title' => [
'S' => $movieName,
],
'year' => [
'N' => $movieYear,
],
]
];
$attributes = ["rating" =>
[
'AttributeName' => 'rating',
'AttributeType' => 'N',
'Value' => $rating,
],
'plot' => [
'AttributeName' => 'plot',
'AttributeType' => 'S',
'Value' => $plot,
]
];
$service->updateItemAttributesByKey($tableName, $key, $attributes);
echo "Movie added and updated.";
$batch = json_decode(loadMovieData());
$service->writeBatch($tableName, $batch);
$movie = $service->getItemByKey($tableName, $key);
echo "\nThe movie {$movie['Item']['title']['S']} was released in {$movie['Item']['year']['N']}.\n";
echo "What rating would you like to give {$movie['Item']['title']['S']}?\n";
$rating = 0;
while (!is_numeric($rating) || intval($rating) != $rating || $rating < 1 || $rating > 10) {
$rating = testable_readline("Rating (1-10): ");
}
$service->updateItemAttributeByKey($tableName, $key, 'rating', 'N', $rating);
$movie = $service->getItemByKey($tableName, $key);
echo "Ok, you have rated {$movie['Item']['title']['S']} as a {$movie['Item']['rating']['N']}\n";
$service->deleteItemByKey($tableName, $key);
echo "But, bad news, this was a trap. That movie has now been deleted because of your rating...harsh.\n";
echo "That's okay though. The book was better. Now, for something lighter, in what year were you born?\n";
$birthYear = "not a number";
while (!is_numeric($birthYear) || $birthYear >= date("Y")) {
$birthYear = testable_readline("Birth year: ");
}
$birthKey = [
'Key' => [
'year' => [
'N' => "$birthYear",
],
],
];
$result = $service->query($tableName, $birthKey);
$marshal = new Marshaler();
echo "Here are the movies in our collection released the year you were born:\n";
$oops = "Oops! There were no movies released in that year (that we know of).\n";
$display = "";
foreach ($result['Items'] as $movie) {
$movie = $marshal->unmarshalItem($movie);
$display .= $movie['title'] . "\n";
}
echo ($display) ?: $oops;
$yearsKey = [
'Key' => [
'year' => [
'N' => [
'minRange' => 1990,
'maxRange' => 1999,
],
],
],
];
$filter = "year between 1990 and 1999";
echo "\nHere's a list of all the movies released in the 90s:\n";
$result = $service->scan($tableName, $yearsKey, $filter);
foreach ($result['Items'] as $movie) {
$movie = $marshal->unmarshalItem($movie);
echo $movie['title'] . "\n";
}
echo "\nCleaning up this demo by deleting table $tableName...\n";
$service->deleteTable($tableName);
}
}
```
+ 有关 API 详细信息，请参阅《适用于 PHP 的 AWS SDK API 参考》**中的以下主题。
+ [BatchWriteItem](https://docs.aws.amazon.com/goto/SdkForPHPV3/dynamodb-2012-08-10/BatchWriteItem)
+ [CreateTable](https://docs.aws.amazon.com/goto/SdkForPHPV3/dynamodb-2012-08-10/CreateTable)
+ [DeleteItem](https://docs.aws.amazon.com/goto/SdkForPHPV3/dynamodb-2012-08-10/DeleteItem)
+ [DeleteTable](https://docs.aws.amazon.com/goto/SdkForPHPV3/dynamodb-2012-08-10/DeleteTable)
+ [DescribeTable](https://docs.aws.amazon.com/goto/SdkForPHPV3/dynamodb-2012-08-10/DescribeTable)
+ [GetItem](https://docs.aws.amazon.com/goto/SdkForPHPV3/dynamodb-2012-08-10/GetItem)
+ [PutItem](https://docs.aws.amazon.com/goto/SdkForPHPV3/dynamodb-2012-08-10/PutItem)
+ [Query](https://docs.aws.amazon.com/goto/SdkForPHPV3/dynamodb-2012-08-10/Query)
+ [Scan](https://docs.aws.amazon.com/goto/SdkForPHPV3/dynamodb-2012-08-10/Scan)
+ [UpdateItem](https://docs.aws.amazon.com/goto/SdkForPHPV3/dynamodb-2012-08-10/UpdateItem)
------
#### [ Python ]
**适用于 Python 的 SDK（Boto3）**
查看 GitHub，了解更多信息。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/python/example_code/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
创建封装 DynamoDB 表的类。
```
from decimal import Decimal
from io import BytesIO
import json
import logging
import os
from pprint import pprint
import requests
from zipfile import ZipFile
import boto3
from boto3.dynamodb.conditions import Key
from botocore.exceptions import ClientError
from question import Question
logger = logging.getLogger(__name__)
class Movies:
"""Encapsulates an Amazon DynamoDB table of movie data.
Example data structure for a movie record in this table:
{
"year": 1999,
"title": "For Love of the Game",
"info": {
"directors": ["Sam Raimi"],
"release_date": "1999-09-15T00:00:00Z",
"rating": 6.3,
"plot": "A washed up pitcher flashes through his career.",
"rank": 4987,
"running_time_secs": 8220,
"actors": [
"Kevin Costner",
"Kelly Preston",
"John C. Reilly"
]
}
}
"""
def __init__(self, dyn_resource):
"""
:param dyn_resource: A Boto3 DynamoDB resource.
"""
self.dyn_resource = dyn_resource
# The table variable is set during the scenario in the call to
# 'exists' if the table exists. Otherwise, it is set by 'create_table'.
self.table = None
def exists(self, table_name):
"""
Determines whether a table exists. As a side effect, stores the table in
a member variable.
:param table_name: The name of the table to check.
:return: True when the table exists; otherwise, False.
"""
try:
table = self.dyn_resource.Table(table_name)
table.load()
exists = True
except ClientError as err:
if err.response["Error"]["Code"] == "ResourceNotFoundException":
exists = False
else:
logger.error(
"Couldn't check for existence of %s. Here's why: %s: %s",
table_name,
err.response["Error"]["Code"],
err.response["Error"]["Message"],
)
raise
else:
self.table = table
return exists
def create_table(self, table_name):
"""
Creates an Amazon DynamoDB table that can be used to store movie data.
The table uses the release year of the movie as the partition key and the
title as the sort key.
:param table_name: The name of the table to create.
:return: The newly created table.
"""
try:
self.table = self.dyn_resource.create_table(
TableName=table_name,
KeySchema=[
{"AttributeName": "year", "KeyType": "HASH"}, # Partition key
{"AttributeName": "title", "KeyType": "RANGE"}, # Sort key
],
AttributeDefinitions=[
{"AttributeName": "year", "AttributeType": "N"},
{"AttributeName": "title", "AttributeType": "S"},
],
BillingMode='PAY_PER_REQUEST',
)
self.table.wait_until_exists()
except ClientError as err:
logger.error(
"Couldn't create table %s. Here's why: %s: %s",
table_name,
err.response["Error"]["Code"],
err.response["Error"]["Message"],
)
raise
else:
return self.table
def list_tables(self):
"""
Lists the Amazon DynamoDB tables for the current account.
:return: The list of tables.
"""
try:
tables = []
for table in self.dyn_resource.tables.all():
print(table.name)
tables.append(table)
except ClientError as err:
logger.error(
"Couldn't list tables. Here's why: %s: %s",
err.response["Error"]["Code"],
err.response["Error"]["Message"],
)
raise
else:
return tables
def write_batch(self, movies):
"""
Fills an Amazon DynamoDB table with the specified data, using the Boto3
Table.batch_writer() function to put the items in the table.
Inside the context manager, Table.batch_writer builds a list of
requests. On exiting the context manager, Table.batch_writer starts sending
batches of write requests to Amazon DynamoDB and automatically
handles chunking, buffering, and retrying.
:param movies: The data to put in the table. Each item must contain at least
the keys required by the schema that was specified when the
table was created.
"""
try:
with self.table.batch_writer() as writer:
for movie in movies:
writer.put_item(Item=movie)
except ClientError as err:
logger.error(
"Couldn't load data into table %s. Here's why: %s: %s",
self.table.name,
err.response["Error"]["Code"],
err.response["Error"]["Message"],
)
raise
def add_movie(self, title, year, plot, rating):
"""
Adds a movie to the table.
:param title: The title of the movie.
:param year: The release year of the movie.
:param plot: The plot summary of the movie.
:param rating: The quality rating of the movie.
"""
try:
self.table.put_item(
Item={
"year": year,
"title": title,
"info": {"plot": plot, "rating": Decimal(str(rating))},
}
)
except ClientError as err:
logger.error(
"Couldn't add movie %s to table %s. Here's why: %s: %s",
title,
self.table.name,
err.response["Error"]["Code"],
err.response["Error"]["Message"],
)
raise
def get_movie(self, title, year):
"""
Gets movie data from the table for a specific movie.
:param title: The title of the movie.
:param year: The release year of the movie.
:return: The data about the requested movie.
"""
try:
response = self.table.get_item(Key={"year": year, "title": title})
except ClientError as err:
logger.error(
"Couldn't get movie %s from table %s. Here's why: %s: %s",
title,
self.table.name,
err.response["Error"]["Code"],
err.response["Error"]["Message"],
)
raise
else:
return response["Item"]
def update_movie(self, title, year, rating, plot):
"""
Updates rating and plot data for a movie in the table.
:param title: The title of the movie to update.
:param year: The release year of the movie to update.
:param rating: The updated rating to the give the movie.
:param plot: The updated plot summary to give the movie.
:return: The fields that were updated, with their new values.
"""
try:
response = self.table.update_item(
Key={"year": year, "title": title},
UpdateExpression="set info.rating=:r, info.plot=:p",
ExpressionAttributeValues={":r": Decimal(str(rating)), ":p": plot},
ReturnValues="UPDATED_NEW",
)
except ClientError as err:
logger.error(
"Couldn't update movie %s in table %s. Here's why: %s: %s",
title,
self.table.name,
err.response["Error"]["Code"],
err.response["Error"]["Message"],
)
raise
else:
return response["Attributes"]
def query_movies(self, year):
"""
Queries for movies that were released in the specified year.
:param year: The year to query.
:return: The list of movies that were released in the specified year.
"""
try:
response = self.table.query(KeyConditionExpression=Key("year").eq(year))
except ClientError as err:
logger.error(
"Couldn't query for movies released in %s. Here's why: %s: %s",
year,
err.response["Error"]["Code"],
err.response["Error"]["Message"],
)
raise
else:
return response["Items"]
def scan_movies(self, year_range):
"""
Scans for movies that were released in a range of years.
Uses a projection expression to return a subset of data for each movie.
:param year_range: The range of years to retrieve.
:return: The list of movies released in the specified years.
"""
movies = []
scan_kwargs = {
"FilterExpression": Key("year").between(
year_range["first"], year_range["second"]
),
"ProjectionExpression": "#yr, title, info.rating",
"ExpressionAttributeNames": {"#yr": "year"},
}
try:
done = False
start_key = None
while not done:
if start_key:
scan_kwargs["ExclusiveStartKey"] = start_key
response = self.table.scan(**scan_kwargs)
movies.extend(response.get("Items", []))
start_key = response.get("LastEvaluatedKey", None)
done = start_key is None
except ClientError as err:
logger.error(
"Couldn't scan for movies. Here's why: %s: %s",
err.response["Error"]["Code"],
err.response["Error"]["Message"],
)
raise
return movies
def delete_movie(self, title, year):
"""
Deletes a movie from the table.
:param title: The title of the movie to delete.
:param year: The release year of the movie to delete.
"""
try:
self.table.delete_item(Key={"year": year, "title": title})
except ClientError as err:
logger.error(
"Couldn't delete movie %s. Here's why: %s: %s",
title,
err.response["Error"]["Code"],
err.response["Error"]["Message"],
)
raise
def delete_table(self):
"""
Deletes the table.
"""
try:
self.table.delete()
self.table = None
except ClientError as err:
logger.error(
"Couldn't delete table. Here's why: %s: %s",
err.response["Error"]["Code"],
err.response["Error"]["Message"],
)
raise
```
创建帮助函数以下载并提取示例 JSON 文件。
```
def get_sample_movie_data(movie_file_name):
"""
Gets sample movie data, either from a local file or by first downloading it from
the Amazon DynamoDB developer guide.
:param movie_file_name: The local file name where the movie data is stored in JSON format.
:return: The movie data as a dict.
"""
if not os.path.isfile(movie_file_name):
print(f"Downloading {movie_file_name}...")
movie_content = requests.get(
"https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/samples/moviedata.zip"
)
movie_zip = ZipFile(BytesIO(movie_content.content))
movie_zip.extractall()
try:
with open(movie_file_name) as movie_file:
movie_data = json.load(movie_file, parse_float=Decimal)
except FileNotFoundError:
print(
f"File {movie_file_name} not found. You must first download the file to "
"run this demo. See the README for instructions."
)
raise
else:
# The sample file lists over 4000 movies, return only the first 250.
return movie_data[:250]
```
运行交互式场景以创建表并对其执行操作。
```
def run_scenario(table_name, movie_file_name, dyn_resource):
logging.basicConfig(level=logging.INFO, format="%(levelname)s: %(message)s")
print("-" * 88)
print("Welcome to the Amazon DynamoDB getting started demo.")
print("-" * 88)
movies = Movies(dyn_resource)
movies_exists = movies.exists(table_name)
if not movies_exists:
print(f"\nCreating table {table_name}...")
movies.create_table(table_name)
print(f"\nCreated table {movies.table.name}.")
my_movie = Question.ask_questions(
[
Question(
"title", "Enter the title of a movie you want to add to the table: "
),
Question("year", "What year was it released? ", Question.is_int),
Question(
"rating",
"On a scale of 1 - 10, how do you rate it? ",
Question.is_float,
Question.in_range(1, 10),
),
Question("plot", "Summarize the plot for me: "),
]
)
movies.add_movie(**my_movie)
print(f"\nAdded '{my_movie['title']}' to '{movies.table.name}'.")
print("-" * 88)
movie_update = Question.ask_questions(
[
Question(
"rating",
f"\nLet's update your movie.\nYou rated it {my_movie['rating']}, what new "
f"rating would you give it? ",
Question.is_float,
Question.in_range(1, 10),
),
Question(
"plot",
f"You summarized the plot as '{my_movie['plot']}'.\nWhat would you say now? ",
),
]
)
my_movie.update(movie_update)
updated = movies.update_movie(**my_movie)
print(f"\nUpdated '{my_movie['title']}' with new attributes:")
pprint(updated)
print("-" * 88)
if not movies_exists:
movie_data = get_sample_movie_data(movie_file_name)
print(f"\nReading data from '{movie_file_name}' into your table.")
movies.write_batch(movie_data)
print(f"\nWrote {len(movie_data)} movies into {movies.table.name}.")
print("-" * 88)
title = "The Lord of the Rings: The Fellowship of the Ring"
if Question.ask_question(
f"Let's move on...do you want to get info about '{title}'? (y/n) ",
Question.is_yesno,
):
movie = movies.get_movie(title, 2001)
print("\nHere's what I found:")
pprint(movie)
print("-" * 88)
ask_for_year = True
while ask_for_year:
release_year = Question.ask_question(
f"\nLet's get a list of movies released in a given year. Enter a year between "
f"1972 and 2018: ",
Question.is_int,
Question.in_range(1972, 2018),
)
releases = movies.query_movies(release_year)
if releases:
print(f"There were {len(releases)} movies released in {release_year}:")
for release in releases:
print(f"\t{release['title']}")
ask_for_year = False
else:
print(f"I don't know about any movies released in {release_year}!")
ask_for_year = Question.ask_question(
"Try another year? (y/n) ", Question.is_yesno
)
print("-" * 88)
years = Question.ask_questions(
[
Question(
"first",
f"\nNow let's scan for movies released in a range of years. Enter a year: ",
Question.is_int,
Question.in_range(1972, 2018),
),
Question(
"second",
"Now enter another year: ",
Question.is_int,
Question.in_range(1972, 2018),
),
]
)
releases = movies.scan_movies(years)
if releases:
count = Question.ask_question(
f"\nFound {len(releases)} movies. How many do you want to see? ",
Question.is_int,
Question.in_range(1, len(releases)),
)
print(f"\nHere are your {count} movies:\n")
pprint(releases[:count])
else:
print(
f"I don't know about any movies released between {years['first']} "
f"and {years['second']}."
)
print("-" * 88)
if Question.ask_question(
f"\nLet's remove your movie from the table. Do you want to remove "
f"'{my_movie['title']}'? (y/n)",
Question.is_yesno,
):
movies.delete_movie(my_movie["title"], my_movie["year"])
print(f"\nRemoved '{my_movie['title']}' from the table.")
print("-" * 88)
if Question.ask_question(f"\nDelete the table? (y/n) ", Question.is_yesno):
movies.delete_table()
print(f"Deleted {table_name}.")
else:
print(
"Don't forget to delete the table when you're done or you might incur "
"charges on your account."
)
print("\nThanks for watching!")
print("-" * 88)
if __name__ == "__main__":
try:
run_scenario(
"doc-example-table-movies", "moviedata.json", boto3.resource("dynamodb")
)
except Exception as e:
print(f"Something went wrong with the demo! Here's what: {e}")
```
此场景使用以下帮助程序类在命令提示符处提问。
```
class Question:
"""
A helper class to ask questions at a command prompt and validate and convert
the answers.
"""
def __init__(self, key, question, *validators):
"""
:param key: The key that is used for storing the answer in a dict, when
multiple questions are asked in a set.
:param question: The question to ask.
:param validators: The answer is passed through the list of validators until
one fails or they all pass. Validators may also convert the
answer to another form, such as from a str to an int.
"""
self.key = key
self.question = question
self.validators = Question.non_empty, *validators
@staticmethod
def ask_questions(questions):
"""
Asks a set of questions and stores the answers in a dict.
:param questions: The list of questions to ask.
:return: A dict of answers.
"""
answers = {}
for question in questions:
answers[question.key] = Question.ask_question(
question.question, *question.validators
)
return answers
@staticmethod
def ask_question(question, *validators):
"""
Asks a single question and validates it against a list of validators.
When an answer fails validation, the complaint is printed and the question
is asked again.
:param question: The question to ask.
:param validators: The list of validators that the answer must pass.
:return: The answer, converted to its final form by the validators.
"""
answer = None
while answer is None:
answer = input(question)
for validator in validators:
answer, complaint = validator(answer)
if answer is None:
print(complaint)
break
return answer
@staticmethod
def non_empty(answer):
"""
Validates that the answer is not empty.
:return: The non-empty answer, or None.
"""
return answer if answer != "" else None, "I need an answer. Please?"
@staticmethod
def is_yesno(answer):
"""
Validates a yes/no answer.
:return: True when the answer is 'y'; otherwise, False.
"""
return answer.lower() == "y", ""
@staticmethod
def is_int(answer):
"""
Validates that the answer can be converted to an int.
:return: The int answer; otherwise, None.
"""
try:
int_answer = int(answer)
except ValueError:
int_answer = None
return int_answer, f"{answer} must be a valid integer."
@staticmethod
def is_letter(answer):
"""
Validates that the answer is a letter.
:return The letter answer, converted to uppercase; otherwise, None.
"""
return (
answer.upper() if answer.isalpha() else None,
f"{answer} must be a single letter.",
)
@staticmethod
def is_float(answer):
"""
Validate that the answer can be converted to a float.
:return The float answer; otherwise, None.
"""
try:
float_answer = float(answer)
except ValueError:
float_answer = None
return float_answer, f"{answer} must be a valid float."
@staticmethod
def in_range(lower, upper):
"""
Validate that the answer is within a range. The answer must be of a type that can
be compared to the lower and upper bounds.
:return: The answer, if it is within the range; otherwise, None.
"""
def _validate(answer):
return (
answer if lower <= answer <= upper else None,
f"{answer} must be between {lower} and {upper}.",
)
return _validate
```
+ 有关 API 详细信息，请参阅《AWS SDK for Python (Boto3) API Reference》**中的以下主题。
+ [BatchWriteItem](https://docs.aws.amazon.com/goto/boto3/dynamodb-2012-08-10/BatchWriteItem)
+ [CreateTable](https://docs.aws.amazon.com/goto/boto3/dynamodb-2012-08-10/CreateTable)
+ [DeleteItem](https://docs.aws.amazon.com/goto/boto3/dynamodb-2012-08-10/DeleteItem)
+ [DeleteTable](https://docs.aws.amazon.com/goto/boto3/dynamodb-2012-08-10/DeleteTable)
+ [DescribeTable](https://docs.aws.amazon.com/goto/boto3/dynamodb-2012-08-10/DescribeTable)
+ [GetItem](https://docs.aws.amazon.com/goto/boto3/dynamodb-2012-08-10/GetItem)
+ [PutItem](https://docs.aws.amazon.com/goto/boto3/dynamodb-2012-08-10/PutItem)
+ [Query](https://docs.aws.amazon.com/goto/boto3/dynamodb-2012-08-10/Query)
+ [Scan](https://docs.aws.amazon.com/goto/boto3/dynamodb-2012-08-10/Scan)
+ [UpdateItem](https://docs.aws.amazon.com/goto/boto3/dynamodb-2012-08-10/UpdateItem)
------
#### [ Ruby ]
**适用于 Ruby 的 SDK**
查看 GitHub，了解更多信息。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/ruby/example_code/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
创建封装 DynamoDB 表的类。
```
# Creates an Amazon DynamoDB table that can be used to store movie data.
# The table uses the release year of the movie as the partition key and the
# title as the sort key.
#
# @param table_name [String] The name of the table to create.
# @return [Aws::DynamoDB::Table] The newly created table.
def create_table(table_name)
@table = @dynamo_resource.create_table(
table_name: table_name,
key_schema: [
{ attribute_name: 'year', key_type: 'HASH' }, # Partition key
{ attribute_name: 'title', key_type: 'RANGE' } # Sort key
],
attribute_definitions: [
{ attribute_name: 'year', attribute_type: 'N' },
{ attribute_name: 'title', attribute_type: 'S' }
],
billing_mode: 'PAY_PER_REQUEST'
)
@dynamo_resource.client.wait_until(:table_exists, table_name: table_name)
@table
rescue Aws::DynamoDB::Errors::ServiceError => e
@logger.error("Failed create table #{table_name}:\n#{e.code}: #{e.message}")
raise
end
```
创建帮助函数以下载并提取示例 JSON 文件。
```
# Gets sample movie data, either from a local file or by first downloading it from
# the Amazon DynamoDB Developer Guide.
#
# @param movie_file_name [String] The local file name where the movie data is stored in JSON format.
# @return [Hash] The movie data as a Hash.
def fetch_movie_data(movie_file_name)
if !File.file?(movie_file_name)
@logger.debug("Downloading #{movie_file_name}...")
movie_content = URI.open(
'https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/samples/moviedata.zip'
)
movie_json = ''
Zip::File.open_buffer(movie_content) do |zip|
zip.each do |entry|
movie_json = entry.get_input_stream.read
end
end
else
movie_json = File.read(movie_file_name)
end
movie_data = JSON.parse(movie_json)
# The sample file lists over 4000 movies. This returns only the first 250.
movie_data.slice(0, 250)
rescue StandardError => e
puts("Failure downloading movie data:\n#{e}")
raise
end
```
运行交互式场景以创建表并对其执行操作。
```
table_name = "doc-example-table-movies-#{rand(10**4)}"
scaffold = Scaffold.new(table_name)
dynamodb_wrapper = DynamoDBBasics.new(table_name)
new_step(1, 'Create a new DynamoDB table if none already exists.')
unless scaffold.exists?(table_name)
puts("\nNo such table: #{table_name}. Creating it...")
scaffold.create_table(table_name)
print "Done!\n".green
end
new_step(2, 'Add a new record to the DynamoDB table.')
my_movie = {}
my_movie[:title] = CLI::UI::Prompt.ask('Enter the title of a movie to add to the table. E.g. The Matrix')
my_movie[:year] = CLI::UI::Prompt.ask('What year was it released? E.g. 1989').to_i
my_movie[:rating] = CLI::UI::Prompt.ask('On a scale of 1 - 10, how do you rate it? E.g. 7').to_i
my_movie[:plot] = CLI::UI::Prompt.ask('Enter a brief summary of the plot. E.g. A man awakens to a new reality.')
dynamodb_wrapper.add_item(my_movie)
puts("\nNew record added:")
puts JSON.pretty_generate(my_movie).green
print "Done!\n".green
new_step(3, 'Update a record in the DynamoDB table.')
my_movie[:rating] = CLI::UI::Prompt.ask("Let's update the movie you added with a new rating, e.g. 3:").to_i
response = dynamodb_wrapper.update_item(my_movie)
puts("Updated '#{my_movie[:title]}' with new attributes:")
puts JSON.pretty_generate(response).green
print "Done!\n".green
new_step(4, 'Get a record from the DynamoDB table.')
puts("Searching for #{my_movie[:title]} (#{my_movie[:year]})...")
response = dynamodb_wrapper.get_item(my_movie[:title], my_movie[:year])
puts JSON.pretty_generate(response).green
print "Done!\n".green
new_step(5, 'Write a batch of items into the DynamoDB table.')
download_file = 'moviedata.json'
puts("Downloading movie database to #{download_file}...")
movie_data = scaffold.fetch_movie_data(download_file)
puts("Writing movie data from #{download_file} into your table...")
scaffold.write_batch(movie_data)
puts("Records added: #{movie_data.length}.")
print "Done!\n".green
new_step(5, 'Query for a batch of items by key.')
loop do
release_year = CLI::UI::Prompt.ask('Enter a year between 1972 and 2018, e.g. 1999:').to_i
results = dynamodb_wrapper.query_items(release_year)
if results.any?
puts("There were #{results.length} movies released in #{release_year}:")
results.each do |movie|
print "\t #{movie['title']}".green
end
break
else
continue = CLI::UI::Prompt.ask("Found no movies released in #{release_year}! Try another year? (y/n)")
break unless continue.eql?('y')
end
end
print "\nDone!\n".green
new_step(6, 'Scan for a batch of items using a filter expression.')
years = {}
years[:start] = CLI::UI::Prompt.ask('Enter a starting year between 1972 and 2018:')
years[:end] = CLI::UI::Prompt.ask('Enter an ending year between 1972 and 2018:')
releases = dynamodb_wrapper.scan_items(years)
if !releases.empty?
puts("Found #{releases.length} movies.")
count = Question.ask(
'How many do you want to see? ', method(:is_int), in_range(1, releases.length)
)
puts("Here are your #{count} movies:")
releases.take(count).each do |release|
puts("\t#{release['title']}")
end
else
puts("I don't know about any movies released between #{years[:start]} "\
"and #{years[:end]}.")
end
print "\nDone!\n".green
new_step(7, 'Delete an item from the DynamoDB table.')
answer = CLI::UI::Prompt.ask("Do you want to remove '#{my_movie[:title]}'? (y/n) ")
if answer.eql?('y')
dynamodb_wrapper.delete_item(my_movie[:title], my_movie[:year])
puts("Removed '#{my_movie[:title]}' from the table.")
print "\nDone!\n".green
end
new_step(8, 'Delete the DynamoDB table.')
answer = CLI::UI::Prompt.ask('Delete the table? (y/n)')
if answer.eql?('y')
scaffold.delete_table
puts("Deleted #{table_name}.")
else
puts("Don't forget to delete the table when you're done!")
end
print "\nThanks for watching!\n".green
rescue Aws::Errors::ServiceError
puts('Something went wrong with the demo.')
rescue Errno::ENOENT
true
end
```
+ 有关 API 详细信息，请参阅《适用于 Ruby 的 AWS SDK API Reference》**中的以下主题。
+ [BatchWriteItem](https://docs.aws.amazon.com/goto/SdkForRubyV3/dynamodb-2012-08-10/BatchWriteItem)
+ [CreateTable](https://docs.aws.amazon.com/goto/SdkForRubyV3/dynamodb-2012-08-10/CreateTable)
+ [DeleteItem](https://docs.aws.amazon.com/goto/SdkForRubyV3/dynamodb-2012-08-10/DeleteItem)
+ [DeleteTable](https://docs.aws.amazon.com/goto/SdkForRubyV3/dynamodb-2012-08-10/DeleteTable)
+ [DescribeTable](https://docs.aws.amazon.com/goto/SdkForRubyV3/dynamodb-2012-08-10/DescribeTable)
+ [GetItem](https://docs.aws.amazon.com/goto/SdkForRubyV3/dynamodb-2012-08-10/GetItem)
+ [PutItem](https://docs.aws.amazon.com/goto/SdkForRubyV3/dynamodb-2012-08-10/PutItem)
+ [Query](https://docs.aws.amazon.com/goto/SdkForRubyV3/dynamodb-2012-08-10/Query)
+ [Scan](https://docs.aws.amazon.com/goto/SdkForRubyV3/dynamodb-2012-08-10/Scan)
+ [UpdateItem](https://docs.aws.amazon.com/goto/SdkForRubyV3/dynamodb-2012-08-10/UpdateItem)
------
#### [ SAP ABAP ]
**适用于 SAP ABAP 的 SDK**
查看 GitHub，了解更多信息。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/sap-abap/services/dyn#code-examples)中查找完整示例，了解如何进行设置和运行。
```
" Create an Amazon Dynamo DB table.
TRY.
DATA(lo_session) = /aws1/cl_rt_session_aws=>create( cv_pfl ).
DATA(lo_dyn) = /aws1/cl_dyn_factory=>create( lo_session ).
DATA(lt_keyschema) = VALUE /aws1/cl_dynkeyschemaelement=>tt_keyschema(
( NEW /aws1/cl_dynkeyschemaelement( iv_attributename = 'year'
iv_keytype = 'HASH' ) )
( NEW /aws1/cl_dynkeyschemaelement( iv_attributename = 'title'
iv_keytype = 'RANGE' ) ) ).
DATA(lt_attributedefinitions) = VALUE /aws1/cl_dynattributedefn=>tt_attributedefinitions(
( NEW /aws1/cl_dynattributedefn( iv_attributename = 'year'
iv_attributetype = 'N' ) )
( NEW /aws1/cl_dynattributedefn( iv_attributename = 'title'
iv_attributetype = 'S' ) ) ).
" Adjust read/write capacities as desired.
DATA(lo_dynprovthroughput) = NEW /aws1/cl_dynprovthroughput(
iv_readcapacityunits = 5
iv_writecapacityunits = 5 ).
DATA(oo_result) = lo_dyn->createtable(
it_keyschema = lt_keyschema
iv_tablename = iv_table_name
it_attributedefinitions = lt_attributedefinitions
io_provisionedthroughput = lo_dynprovthroughput ).
" Table creation can take some time. Wait till table exists before returning.
lo_dyn->get_waiter( )->tableexists(
iv_max_wait_time = 200
iv_tablename = iv_table_name ).
MESSAGE 'DynamoDB Table' && iv_table_name && 'created.' TYPE 'I'.
" It throws exception if the table already exists.
CATCH /aws1/cx_dynresourceinuseex INTO DATA(lo_resourceinuseex).
DATA(lv_error) = |"{ lo_resourceinuseex->av_err_code }" - { lo_resourceinuseex->av_err_msg }|.
MESSAGE lv_error TYPE 'E'.
ENDTRY.
" Describe table
TRY.
DATA(lo_table) = lo_dyn->describetable( iv_tablename = iv_table_name ).
DATA(lv_tablename) = lo_table->get_table( )->ask_tablename( ).
MESSAGE 'The table name is ' && lv_tablename TYPE 'I'.
CATCH /aws1/cx_dynresourcenotfoundex.
MESSAGE 'The table does not exist' TYPE 'E'.
ENDTRY.
" Put items into the table.
TRY.
DATA(lo_resp_putitem) = lo_dyn->putitem(
iv_tablename = iv_table_name
it_item = VALUE /aws1/cl_dynattributevalue=>tt_putiteminputattributemap(
( VALUE /aws1/cl_dynattributevalue=>ts_putiteminputattrmap_maprow(
key = 'title' value = NEW /aws1/cl_dynattributevalue( iv_s = 'Jaws' ) ) )
( VALUE /aws1/cl_dynattributevalue=>ts_putiteminputattrmap_maprow(
key = 'year' value = NEW /aws1/cl_dynattributevalue( iv_n = |{ '1975' }| ) ) )
( VALUE /aws1/cl_dynattributevalue=>ts_putiteminputattrmap_maprow(
key = 'rating' value = NEW /aws1/cl_dynattributevalue( iv_n = |{ '7.5' }| ) ) )
) ).
lo_resp_putitem = lo_dyn->putitem(
iv_tablename = iv_table_name
it_item = VALUE /aws1/cl_dynattributevalue=>tt_putiteminputattributemap(
( VALUE /aws1/cl_dynattributevalue=>ts_putiteminputattrmap_maprow(
key = 'title' value = NEW /aws1/cl_dynattributevalue( iv_s = 'Star Wars' ) ) )
( VALUE /aws1/cl_dynattributevalue=>ts_putiteminputattrmap_maprow(
key = 'year' value = NEW /aws1/cl_dynattributevalue( iv_n = |{ '1978' }| ) ) )
( VALUE /aws1/cl_dynattributevalue=>ts_putiteminputattrmap_maprow(
key = 'rating' value = NEW /aws1/cl_dynattributevalue( iv_n = |{ '8.1' }| ) ) )
) ).
lo_resp_putitem = lo_dyn->putitem(
iv_tablename = iv_table_name
it_item = VALUE /aws1/cl_dynattributevalue=>tt_putiteminputattributemap(
( VALUE /aws1/cl_dynattributevalue=>ts_putiteminputattrmap_maprow(
key = 'title' value = NEW /aws1/cl_dynattributevalue( iv_s = 'Speed' ) ) )
( VALUE /aws1/cl_dynattributevalue=>ts_putiteminputattrmap_maprow(
key = 'year' value = NEW /aws1/cl_dynattributevalue( iv_n = |{ '1994' }| ) ) )
( VALUE /aws1/cl_dynattributevalue=>ts_putiteminputattrmap_maprow(
key = 'rating' value = NEW /aws1/cl_dynattributevalue( iv_n = |{ '7.9' }| ) ) )
) ).
" TYPE REF TO /AWSEX/CL_AWS1_dyn_PUT_ITEM_OUTPUT
MESSAGE '3 rows inserted into DynamoDB Table' && iv_table_name TYPE 'I'.
CATCH /aws1/cx_dyncondalcheckfaile00.
MESSAGE 'A condition specified in the operation could not be evaluated.' TYPE 'E'.
CATCH /aws1/cx_dynresourcenotfoundex.
MESSAGE 'The table or index does not exist' TYPE 'E'.
CATCH /aws1/cx_dyntransactconflictex.
MESSAGE 'Another transaction is using the item' TYPE 'E'.
ENDTRY.
" Get item from table.
TRY.
DATA(lo_resp_getitem) = lo_dyn->getitem(
iv_tablename = iv_table_name
it_key = VALUE /aws1/cl_dynattributevalue=>tt_key(
( VALUE /aws1/cl_dynattributevalue=>ts_key_maprow(
key = 'title' value = NEW /aws1/cl_dynattributevalue( iv_s = 'Jaws' ) ) )
( VALUE /aws1/cl_dynattributevalue=>ts_key_maprow(
key = 'year' value = NEW /aws1/cl_dynattributevalue( iv_n = '1975' ) ) )
) ).
DATA(lt_attr) = lo_resp_getitem->get_item( ).
DATA(lo_title) = lt_attr[ key = 'title' ]-value.
DATA(lo_year) = lt_attr[ key = 'year' ]-value.
DATA(lo_rating) = lt_attr[ key = 'year' ]-value.
MESSAGE 'Movie name is: ' && lo_title->get_s( ) TYPE 'I'.
MESSAGE 'Movie year is: ' && lo_year->get_n( ) TYPE 'I'.
MESSAGE 'Movie rating is: ' && lo_rating->get_n( ) TYPE 'I'.
CATCH /aws1/cx_dynresourcenotfoundex.
MESSAGE 'The table or index does not exist' TYPE 'E'.
ENDTRY.
" Query item from table.
TRY.
DATA(lt_attributelist) = VALUE /aws1/cl_dynattributevalue=>tt_attributevaluelist(
( NEW /aws1/cl_dynattributevalue( iv_n = '1975' ) ) ).
DATA(lt_keyconditions) = VALUE /aws1/cl_dyncondition=>tt_keyconditions(
( VALUE /aws1/cl_dyncondition=>ts_keyconditions_maprow(
key = 'year'
value = NEW /aws1/cl_dyncondition(
it_attributevaluelist = lt_attributelist
iv_comparisonoperator = |EQ|
) ) ) ).
DATA(lo_query_result) = lo_dyn->query(
iv_tablename = iv_table_name
it_keyconditions = lt_keyconditions ).
DATA(lt_items) = lo_query_result->get_items( ).
READ TABLE lo_query_result->get_items( ) INTO DATA(lt_item) INDEX 1.
lo_title = lt_item[ key = 'title' ]-value.
lo_year = lt_item[ key = 'year' ]-value.
lo_rating = lt_item[ key = 'rating' ]-value.
MESSAGE 'Movie name is: ' && lo_title->get_s( ) TYPE 'I'.
MESSAGE 'Movie year is: ' && lo_year->get_n( ) TYPE 'I'.
MESSAGE 'Movie rating is: ' && lo_rating->get_n( ) TYPE 'I'.
CATCH /aws1/cx_dynresourcenotfoundex.
MESSAGE 'The table or index does not exist' TYPE 'E'.
ENDTRY.
" Scan items from table.
TRY.
DATA(lo_scan_result) = lo_dyn->scan( iv_tablename = iv_table_name ).
lt_items = lo_scan_result->get_items( ).
" Read the first item and display the attributes.
READ TABLE lo_query_result->get_items( ) INTO lt_item INDEX 1.
lo_title = lt_item[ key = 'title' ]-value.
lo_year = lt_item[ key = 'year' ]-value.
lo_rating = lt_item[ key = 'rating' ]-value.
MESSAGE 'Movie name is: ' && lo_title->get_s( ) TYPE 'I'.
MESSAGE 'Movie year is: ' && lo_year->get_n( ) TYPE 'I'.
MESSAGE 'Movie rating is: ' && lo_rating->get_n( ) TYPE 'I'.
CATCH /aws1/cx_dynresourcenotfoundex.
MESSAGE 'The table or index does not exist' TYPE 'E'.
ENDTRY.
" Update items from table.
TRY.
DATA(lt_attributeupdates) = VALUE /aws1/cl_dynattrvalueupdate=>tt_attributeupdates(
( VALUE /aws1/cl_dynattrvalueupdate=>ts_attributeupdates_maprow(
key = 'rating' value = NEW /aws1/cl_dynattrvalueupdate(
io_value = NEW /aws1/cl_dynattributevalue( iv_n = '7.6' )
iv_action = |PUT| ) ) ) ).
DATA(lt_key) = VALUE /aws1/cl_dynattributevalue=>tt_key(
( VALUE /aws1/cl_dynattributevalue=>ts_key_maprow(
key = 'year' value = NEW /aws1/cl_dynattributevalue( iv_n = '1975' ) ) )
( VALUE /aws1/cl_dynattributevalue=>ts_key_maprow(
key = 'title' value = NEW /aws1/cl_dynattributevalue( iv_s = '1980' ) ) ) ).
DATA(lo_resp) = lo_dyn->updateitem(
iv_tablename = iv_table_name
it_key = lt_key
it_attributeupdates = lt_attributeupdates ).
MESSAGE '1 item updated in DynamoDB Table' && iv_table_name TYPE 'I'.
CATCH /aws1/cx_dyncondalcheckfaile00.
MESSAGE 'A condition specified in the operation could not be evaluated.' TYPE 'E'.
CATCH /aws1/cx_dynresourcenotfoundex.
MESSAGE 'The table or index does not exist' TYPE 'E'.
CATCH /aws1/cx_dyntransactconflictex.
MESSAGE 'Another transaction is using the item' TYPE 'E'.
ENDTRY.
" Delete table.
TRY.
lo_dyn->deletetable( iv_tablename = iv_table_name ).
lo_dyn->get_waiter( )->tablenotexists(
iv_max_wait_time = 200
iv_tablename = iv_table_name ).
MESSAGE 'DynamoDB Table deleted.' TYPE 'I'.
CATCH /aws1/cx_dynresourcenotfoundex.
MESSAGE 'The table or index does not exist' TYPE 'E'.
CATCH /aws1/cx_dynresourceinuseex.
MESSAGE 'The table cannot be deleted as it is in use' TYPE 'E'.
ENDTRY.
```
+ 有关 API 详细信息，请参阅《AWS SDK for SAP ABAP API Reference》**中的以下主题。
+ [BatchWriteItem](https://docs.aws.amazon.com/sdk-for-sap-abap/v1/api/latest/index.html)
+ [CreateTable](https://docs.aws.amazon.com/sdk-for-sap-abap/v1/api/latest/index.html)
+ [DeleteItem](https://docs.aws.amazon.com/sdk-for-sap-abap/v1/api/latest/index.html)
+ [DeleteTable](https://docs.aws.amazon.com/sdk-for-sap-abap/v1/api/latest/index.html)
+ [DescribeTable](https://docs.aws.amazon.com/sdk-for-sap-abap/v1/api/latest/index.html)
+ [GetItem](https://docs.aws.amazon.com/sdk-for-sap-abap/v1/api/latest/index.html)
+ [PutItem](https://docs.aws.amazon.com/sdk-for-sap-abap/v1/api/latest/index.html)
+ [Query](https://docs.aws.amazon.com/sdk-for-sap-abap/v1/api/latest/index.html)
+ [Scan](https://docs.aws.amazon.com/sdk-for-sap-abap/v1/api/latest/index.html)
+ [UpdateItem](https://docs.aws.amazon.com/sdk-for-sap-abap/v1/api/latest/index.html)
------
#### [ Swift ]
**适用于 Swift 的 SDK**
查看 GitHub，了解更多信息。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/swift/example_code/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
一个 Swift 类，用于处理对 SDK for Swift 的 DynamoDB 调用。
```
import AWSDynamoDB
import Foundation
/// An enumeration of error codes representing issues that can arise when using
/// the `MovieTable` class.
enum MoviesError: Error {
/// The specified table wasn't found or couldn't be created.
case TableNotFound
/// The specified item wasn't found or couldn't be created.
case ItemNotFound
/// The Amazon DynamoDB client is not properly initialized.
case UninitializedClient
/// The table status reported by Amazon DynamoDB is not recognized.
case StatusUnknown
/// One or more specified attribute values are invalid or missing.
case InvalidAttributes
}
/// A class representing an Amazon DynamoDB table containing movie
/// information.
public class MovieTable {
var ddbClient: DynamoDBClient?
let tableName: String
/// Create an object representing a movie table in an Amazon DynamoDB
/// database.
///
/// - Parameters:
/// - region: The optional Amazon Region to create the database in.
/// - tableName: The name to assign to the table. If not specified, a
/// random table name is generated automatically.
///
/// > Note: The table is not necessarily available when this function
/// returns. Use `tableExists()` to check for its availability, or
/// `awaitTableActive()` to wait until the table's status is reported as
/// ready to use by Amazon DynamoDB.
///
init(region: String? = nil, tableName: String) async throws {
do {
let config = try await DynamoDBClient.DynamoDBClientConfiguration()
if let region = region {
config.region = region
}
self.ddbClient = DynamoDBClient(config: config)
self.tableName = tableName
try await self.createTable()
} catch {
print("ERROR: ", dump(error, name: "Initializing Amazon DynamoDBClient client"))
throw error
}
}
///
/// Create a movie table in the Amazon DynamoDB data store.
///
private func createTable() async throws {
do {
guard let client = self.ddbClient else {
throw MoviesError.UninitializedClient
}
let input = CreateTableInput(
attributeDefinitions: [
DynamoDBClientTypes.AttributeDefinition(attributeName: "year", attributeType: .n),
DynamoDBClientTypes.AttributeDefinition(attributeName: "title", attributeType: .s)
],
billingMode: DynamoDBClientTypes.BillingMode.payPerRequest,
keySchema: [
DynamoDBClientTypes.KeySchemaElement(attributeName: "year", keyType: .hash),
DynamoDBClientTypes.KeySchemaElement(attributeName: "title", keyType: .range)
],
tableName: self.tableName
)
let output = try await client.createTable(input: input)
if output.tableDescription == nil {
throw MoviesError.TableNotFound
}
} catch {
print("ERROR: createTable:", dump(error))
throw error
}
}
/// Check to see if the table exists online yet.
///
/// - Returns: `true` if the table exists, or `false` if not.
///
func tableExists() async throws -> Bool {
do {
guard let client = self.ddbClient else {
throw MoviesError.UninitializedClient
}
let input = DescribeTableInput(
tableName: tableName
)
let output = try await client.describeTable(input: input)
guard let description = output.table else {
throw MoviesError.TableNotFound
}
return description.tableName == self.tableName
} catch {
print("ERROR: tableExists:", dump(error))
throw error
}
}
///
/// Waits for the table to exist and for its status to be active.
///
func awaitTableActive() async throws {
while try (await self.tableExists() == false) {
do {
let duration = UInt64(0.25 * 1_000_000_000) // Convert .25 seconds to nanoseconds.
try await Task.sleep(nanoseconds: duration)
} catch {
print("Sleep error:", dump(error))
}
}
while try (await self.getTableStatus() != .active) {
do {
let duration = UInt64(0.25 * 1_000_000_000) // Convert .25 seconds to nanoseconds.
try await Task.sleep(nanoseconds: duration)
} catch {
print("Sleep error:", dump(error))
}
}
}
///
/// Deletes the table from Amazon DynamoDB.
///
func deleteTable() async throws {
do {
guard let client = self.ddbClient else {
throw MoviesError.UninitializedClient
}
let input = DeleteTableInput(
tableName: self.tableName
)
_ = try await client.deleteTable(input: input)
} catch {
print("ERROR: deleteTable:", dump(error))
throw error
}
}
/// Get the table's status.
///
/// - Returns: The table status, as defined by the
/// `DynamoDBClientTypes.TableStatus` enum.
///
func getTableStatus() async throws -> DynamoDBClientTypes.TableStatus {
do {
guard let client = self.ddbClient else {
throw MoviesError.UninitializedClient
}
let input = DescribeTableInput(
tableName: self.tableName
)
let output = try await client.describeTable(input: input)
guard let description = output.table else {
throw MoviesError.TableNotFound
}
guard let status = description.tableStatus else {
throw MoviesError.StatusUnknown
}
return status
} catch {
print("ERROR: getTableStatus:", dump(error))
throw error
}
}
/// Populate the movie database from the specified JSON file.
///
/// - Parameter jsonPath: Path to a JSON file containing movie data.
///
func populate(jsonPath: String) async throws {
do {
guard let client = self.ddbClient else {
throw MoviesError.UninitializedClient
}
// Create a Swift `URL` and use it to load the file into a `Data`
// object. Then decode the JSON into an array of `Movie` objects.
let fileUrl = URL(fileURLWithPath: jsonPath)
let jsonData = try Data(contentsOf: fileUrl)
var movieList = try JSONDecoder().decode([Movie].self, from: jsonData)
// Truncate the list to the first 200 entries or so for this example.
if movieList.count > 200 {
movieList = Array(movieList[...199])
}
// Before sending records to the database, break the movie list into
// 25-entry chunks, which is the maximum size of a batch item request.
let count = movieList.count
let chunks = stride(from: 0, to: count, by: 25).map {
Array(movieList[$0 ..< Swift.min($0 + 25, count)])
}
// For each chunk, create a list of write request records and populate
// them with `PutRequest` requests, each specifying one movie from the
// chunk. Once the chunk's items are all in the `PutRequest` list,
// send them to Amazon DynamoDB using the
// `DynamoDBClient.batchWriteItem()` function.
for chunk in chunks {
var requestList: [DynamoDBClientTypes.WriteRequest] = []
for movie in chunk {
let item = try await movie.getAsItem()
let request = DynamoDBClientTypes.WriteRequest(
putRequest: .init(
item: item
)
)
requestList.append(request)
}
let input = BatchWriteItemInput(requestItems: [tableName: requestList])
_ = try await client.batchWriteItem(input: input)
}
} catch {
print("ERROR: populate:", dump(error))
throw error
}
}
/// Add a movie specified as a `Movie` structure to the Amazon DynamoDB
/// table.
///
/// - Parameter movie: The `Movie` to add to the table.
///
func add(movie: Movie) async throws {
do {
guard let client = self.ddbClient else {
throw MoviesError.UninitializedClient
}
// Get a DynamoDB item containing the movie data.
let item = try await movie.getAsItem()
// Send the `PutItem` request to Amazon DynamoDB.
let input = PutItemInput(
item: item,
tableName: self.tableName
)
_ = try await client.putItem(input: input)
} catch {
print("ERROR: add movie:", dump(error))
throw error
}
}
/// Given a movie's details, add a movie to the Amazon DynamoDB table.
///
/// - Parameters:
/// - title: The movie's title as a `String`.
/// - year: The release year of the movie (`Int`).
/// - rating: The movie's rating if available (`Double`; default is
/// `nil`).
/// - plot: A summary of the movie's plot (`String`; default is `nil`,
/// indicating no plot summary is available).
///
func add(title: String, year: Int, rating: Double? = nil,
plot: String? = nil) async throws
{
do {
let movie = Movie(title: title, year: year, rating: rating, plot: plot)
try await self.add(movie: movie)
} catch {
print("ERROR: add with fields:", dump(error))
throw error
}
}
/// Return a `Movie` record describing the specified movie from the Amazon
/// DynamoDB table.
///
/// - Parameters:
/// - title: The movie's title (`String`).
/// - year: The movie's release year (`Int`).
///
/// - Throws: `MoviesError.ItemNotFound` if the movie isn't in the table.
///
/// - Returns: A `Movie` record with the movie's details.
func get(title: String, year: Int) async throws -> Movie {
do {
guard let client = self.ddbClient else {
throw MoviesError.UninitializedClient
}
let input = GetItemInput(
key: [
"year": .n(String(year)),
"title": .s(title)
],
tableName: self.tableName
)
let output = try await client.getItem(input: input)
guard let item = output.item else {
throw MoviesError.ItemNotFound
}
let movie = try Movie(withItem: item)
return movie
} catch {
print("ERROR: get:", dump(error))
throw error
}
}
/// Get all the movies released in the specified year.
///
/// - Parameter year: The release year of the movies to return.
///
/// - Returns: An array of `Movie` objects describing each matching movie.
///
func getMovies(fromYear year: Int) async throws -> [Movie] {
do {
guard let client = self.ddbClient else {
throw MoviesError.UninitializedClient
}
let input = QueryInput(
expressionAttributeNames: [
"#y": "year"
],
expressionAttributeValues: [
":y": .n(String(year))
],
keyConditionExpression: "#y = :y",
tableName: self.tableName
)
// Use "Paginated" to get all the movies.
// This lets the SDK handle the 'lastEvaluatedKey' property in "QueryOutput".
let pages = client.queryPaginated(input: input)
var movieList: [Movie] = []
for try await page in pages {
guard let items = page.items else {
print("Error: no items returned.")
continue
}
// Convert the found movies into `Movie` objects and return an array
// of them.
for item in items {
let movie = try Movie(withItem: item)
movieList.append(movie)
}
}
return movieList
} catch {
print("ERROR: getMovies:", dump(error))
throw error
}
}
/// Return an array of `Movie` objects released in the specified range of
/// years.
///
/// - Parameters:
/// - firstYear: The first year of movies to return.
/// - lastYear: The last year of movies to return.
/// - startKey: A starting point to resume processing; always use `nil`.
///
/// - Returns: An array of `Movie` objects describing the matching movies.
///
/// > Note: The `startKey` parameter is used by this function when
/// recursively calling itself, and should always be `nil` when calling
/// directly.
///
func getMovies(firstYear: Int, lastYear: Int,
startKey: [Swift.String: DynamoDBClientTypes.AttributeValue]? = nil)
async throws -> [Movie]
{
do {
var movieList: [Movie] = []
guard let client = self.ddbClient else {
throw MoviesError.UninitializedClient
}
let input = ScanInput(
consistentRead: true,
exclusiveStartKey: startKey,
expressionAttributeNames: [
"#y": "year" // `year` is a reserved word, so use `#y` instead.
],
expressionAttributeValues: [
":y1": .n(String(firstYear)),
":y2": .n(String(lastYear))
],
filterExpression: "#y BETWEEN :y1 AND :y2",
tableName: self.tableName
)
let pages = client.scanPaginated(input: input)
for try await page in pages {
guard let items = page.items else {
print("Error: no items returned.")
continue
}
// Build an array of `Movie` objects for the returned items.
for item in items {
let movie = try Movie(withItem: item)
movieList.append(movie)
}
}
return movieList
} catch {
print("ERROR: getMovies with scan:", dump(error))
throw error
}
}
/// Update the specified movie with new `rating` and `plot` information.
///
/// - Parameters:
/// - title: The title of the movie to update.
/// - year: The release year of the movie to update.
/// - rating: The new rating for the movie.
/// - plot: The new plot summary string for the movie.
///
/// - Returns: An array of mappings of attribute names to their new
/// listing each item actually changed. Items that didn't need to change
/// aren't included in this list. `nil` if no changes were made.
///
func update(title: String, year: Int, rating: Double? = nil, plot: String? = nil) async throws
-> [Swift.String: DynamoDBClientTypes.AttributeValue]?
{
do {
guard let client = self.ddbClient else {
throw MoviesError.UninitializedClient
}
// Build the update expression and the list of expression attribute
// values. Include only the information that's changed.
var expressionParts: [String] = []
var attrValues: [Swift.String: DynamoDBClientTypes.AttributeValue] = [:]
if rating != nil {
expressionParts.append("info.rating=:r")
attrValues[":r"] = .n(String(rating!))
}
if plot != nil {
expressionParts.append("info.plot=:p")
attrValues[":p"] = .s(plot!)
}
let expression = "set \(expressionParts.joined(separator: ", "))"
let input = UpdateItemInput(
// Create substitution tokens for the attribute values, to ensure
// no conflicts in expression syntax.
expressionAttributeValues: attrValues,
// The key identifying the movie to update consists of the release
// year and title.
key: [
"year": .n(String(year)),
"title": .s(title)
],
returnValues: .updatedNew,
tableName: self.tableName,
updateExpression: expression
)
let output = try await client.updateItem(input: input)
guard let attributes: [Swift.String: DynamoDBClientTypes.AttributeValue] = output.attributes else {
throw MoviesError.InvalidAttributes
}
return attributes
} catch {
print("ERROR: update:", dump(error))
throw error
}
}
/// Delete a movie, given its title and release year.
///
/// - Parameters:
/// - title: The movie's title.
/// - year: The movie's release year.
///
func delete(title: String, year: Int) async throws {
do {
guard let client = self.ddbClient else {
throw MoviesError.UninitializedClient
}
let input = DeleteItemInput(
key: [
"year": .n(String(year)),
"title": .s(title)
],
tableName: self.tableName
)
_ = try await client.deleteItem(input: input)
} catch {
print("ERROR: delete:", dump(error))
throw error
}
}
}
```
MovieTable 类用来表示电影的结构。
```
import Foundation
import AWSDynamoDB
/// The optional details about a movie.
public struct Details: Codable {
/// The movie's rating, if available.
var rating: Double?
/// The movie's plot, if available.
var plot: String?
}
/// A structure describing a movie. The `year` and `title` properties are
/// required and are used as the key for Amazon DynamoDB operations. The
/// `info` sub-structure's two properties, `rating` and `plot`, are optional.
public struct Movie: Codable {
/// The year in which the movie was released.
var year: Int
/// The movie's title.
var title: String
/// A `Details` object providing the optional movie rating and plot
/// information.
var info: Details
/// Create a `Movie` object representing a movie, given the movie's
/// details.
///
/// - Parameters:
/// - title: The movie's title (`String`).
/// - year: The year in which the movie was released (`Int`).
/// - rating: The movie's rating (optional `Double`).
/// - plot: The movie's plot (optional `String`)
init(title: String, year: Int, rating: Double? = nil, plot: String? = nil) {
self.title = title
self.year = year
self.info = Details(rating: rating, plot: plot)
}
/// Create a `Movie` object representing a movie, given the movie's
/// details.
///
/// - Parameters:
/// - title: The movie's title (`String`).
/// - year: The year in which the movie was released (`Int`).
/// - info: The optional rating and plot information for the movie in a
/// `Details` object.
init(title: String, year: Int, info: Details?){
self.title = title
self.year = year
if info != nil {
self.info = info!
} else {
self.info = Details(rating: nil, plot: nil)
}
}
///
/// Return a new `MovieTable` object, given an array mapping string to Amazon
/// DynamoDB attribute values.
///
/// - Parameter item: The item information provided to the form used by
/// DynamoDB. This is an array of strings mapped to
/// `DynamoDBClientTypes.AttributeValue` values.
init(withItem item: [Swift.String:DynamoDBClientTypes.AttributeValue]) throws {
// Read the attributes.
guard let titleAttr = item["title"],
let yearAttr = item["year"] else {
throw MoviesError.ItemNotFound
}
let infoAttr = item["info"] ?? nil
// Extract the values of the title and year attributes.
if case .s(let titleVal) = titleAttr {
self.title = titleVal
} else {
throw MoviesError.InvalidAttributes
}
if case .n(let yearVal) = yearAttr {
self.year = Int(yearVal)!
} else {
throw MoviesError.InvalidAttributes
}
// Extract the rating and/or plot from the `info` attribute, if
// they're present.
var rating: Double? = nil
var plot: String? = nil
if infoAttr != nil, case .m(let infoVal) = infoAttr {
let ratingAttr = infoVal["rating"] ?? nil
let plotAttr = infoVal["plot"] ?? nil
if ratingAttr != nil, case .n(let ratingVal) = ratingAttr {
rating = Double(ratingVal) ?? nil
}
if plotAttr != nil, case .s(let plotVal) = plotAttr {
plot = plotVal
}
}
self.info = Details(rating: rating, plot: plot)
}
///
/// Return an array mapping attribute names to Amazon DynamoDB attribute
/// values, representing the contents of the `Movie` record as a DynamoDB
/// item.
///
/// - Returns: The movie item as an array of type
/// `[Swift.String:DynamoDBClientTypes.AttributeValue]`.
///
func getAsItem() async throws -> [Swift.String:DynamoDBClientTypes.AttributeValue] {
// Build the item record, starting with the year and title, which are
// always present.
var item: [Swift.String:DynamoDBClientTypes.AttributeValue] = [
"year": .n(String(self.year)),
"title": .s(self.title)
]
// Add the `info` field with the rating and/or plot if they're
// available.
var details: [Swift.String:DynamoDBClientTypes.AttributeValue] = [:]
if (self.info.rating != nil || self.info.plot != nil) {
if self.info.rating != nil {
details["rating"] = .n(String(self.info.rating!))
}
if self.info.plot != nil {
details["plot"] = .s(self.info.plot!)
}
}
item["info"] = .m(details)
return item
}
}
```
一个使用 MovieTable 类访问 DynamoDB 数据库的程序。
```
import ArgumentParser
import ClientRuntime
import Foundation
import AWSDynamoDB
@testable import MovieList
extension String {
// Get the directory if the string is a file path.
func directory() -> String {
guard let lastIndex = lastIndex(of: "/") else {
print("Error: String directory separator not found.")
return ""
}
return String(self[...lastIndex])
}
}
struct ExampleCommand: ParsableCommand {
@Argument(help: "The path of the sample movie data JSON file.")
var jsonPath: String = #file.directory() + "../../../../../resources/sample_files/movies.json"
@Option(help: "The AWS Region to run AWS API calls in.")
var awsRegion: String?
@Option(
help: ArgumentHelp("The level of logging for the Swift SDK to perform."),
completion: .list([
"critical",
"debug",
"error",
"info",
"notice",
"trace",
"warning"
])
)
var logLevel: String = "error"
/// Configuration details for the command.
static var configuration = CommandConfiguration(
commandName: "basics",
abstract: "A basic scenario demonstrating the usage of Amazon DynamoDB.",
discussion: """
An example showing how to use Amazon DynamoDB to perform a series of
common database activities on a simple movie database.
"""
)
/// Called by ``main()`` to asynchronously run the AWS example.
func runAsync() async throws {
print("Welcome to the AWS SDK for Swift basic scenario for Amazon DynamoDB!")
//=====================================================================
// 1. Create the table. The Amazon DynamoDB table is represented by
// the `MovieTable` class.
//=====================================================================
let tableName = "ddb-movies-sample-\(Int.random(in: 1 ... Int.max))"
print("Creating table \"\(tableName)\"...")
let movieDatabase = try await MovieTable(region: awsRegion,
tableName: tableName)
print("\nWaiting for table to be ready to use...")
try await movieDatabase.awaitTableActive()
//=====================================================================
// 2. Add a movie to the table.
//=====================================================================
print("\nAdding a movie...")
try await movieDatabase.add(title: "Avatar: The Way of Water", year: 2022)
try await movieDatabase.add(title: "Not a Real Movie", year: 2023)
//=====================================================================
// 3. Update the plot and rating of the movie using an update
// expression.
//=====================================================================
print("\nAdding details to the added movie...")
_ = try await movieDatabase.update(title: "Avatar: The Way of Water", year: 2022,
rating: 9.2, plot: "It's a sequel.")
//=====================================================================
// 4. Populate the table from the JSON file.
//=====================================================================
print("\nPopulating the movie database from JSON...")
try await movieDatabase.populate(jsonPath: jsonPath)
//=====================================================================
// 5. Get a specific movie by key. In this example, the key is a
// combination of `title` and `year`.
//=====================================================================
print("\nLooking for a movie in the table...")
let gotMovie = try await movieDatabase.get(title: "This Is the End", year: 2013)
print("Found the movie \"\(gotMovie.title)\", released in \(gotMovie.year).")
print("Rating: \(gotMovie.info.rating ?? 0.0).")
print("Plot summary: \(gotMovie.info.plot ?? "None.")")
//=====================================================================
// 6. Delete a movie.
//=====================================================================
print("\nDeleting the added movie...")
try await movieDatabase.delete(title: "Avatar: The Way of Water", year: 2022)
//=====================================================================
// 7. Use a query with a key condition expression to return all movies
// released in a given year.
//=====================================================================
print("\nGetting movies released in 1994...")
let movieList = try await movieDatabase.getMovies(fromYear: 1994)
for movie in movieList {
print(" \(movie.title)")
}
//=====================================================================
// 8. Use `scan()` to return movies released in a range of years.
//=====================================================================
print("\nGetting movies released between 1993 and 1997...")
let scannedMovies = try await movieDatabase.getMovies(firstYear: 1993, lastYear: 1997)
for movie in scannedMovies {
print(" \(movie.title) (\(movie.year))")
}
//=====================================================================
// 9. Delete the table.
//=====================================================================
print("\nDeleting the table...")
try await movieDatabase.deleteTable()
}
}
@main
struct Main {
static func main() async {
let args = Array(CommandLine.arguments.dropFirst())
do {
let command = try ExampleCommand.parse(args)
try await command.runAsync()
} catch {
ExampleCommand.exit(withError: error)
}
}
}
```
+ 有关 API 详细信息，请参阅《AWS SDK for Swift API Reference》**中的以下主题。
+ [BatchWriteItem](https://sdk.amazonaws.com/swift/api/awsdynamodb/latest/documentation/awsdynamodb/dynamodbclient/batchwriteitem(input:))
+ [CreateTable](https://sdk.amazonaws.com/swift/api/awsdynamodb/latest/documentation/awsdynamodb/dynamodbclient/createtable(input:))
+ [DeleteItem](https://sdk.amazonaws.com/swift/api/awsdynamodb/latest/documentation/awsdynamodb/dynamodbclient/deleteitem(input:))
+ [DeleteTable](https://sdk.amazonaws.com/swift/api/awsdynamodb/latest/documentation/awsdynamodb/dynamodbclient/deletetable(input:))
+ [DescribeTable](https://sdk.amazonaws.com/swift/api/awsdynamodb/latest/documentation/awsdynamodb/dynamodbclient/describetable(input:))
+ [GetItem](https://sdk.amazonaws.com/swift/api/awsdynamodb/latest/documentation/awsdynamodb/dynamodbclient/getitem(input:))
+ [PutItem](https://sdk.amazonaws.com/swift/api/awsdynamodb/latest/documentation/awsdynamodb/dynamodbclient/putitem(input:))
+ [Query](https://sdk.amazonaws.com/swift/api/awsdynamodb/latest/documentation/awsdynamodb/dynamodbclient/query(input:))
+ [Scan](https://sdk.amazonaws.com/swift/api/awsdynamodb/latest/documentation/awsdynamodb/dynamodbclient/scan(input:))
+ [UpdateItem](https://sdk.amazonaws.com/swift/api/awsdynamodb/latest/documentation/awsdynamodb/dynamodbclient/updateitem(input:))
------
有关 AWS SDK 开发人员指南和代码示例的完整列表，请参阅 [结合使用 DynamoDB 与 AWS SDK](sdk-general-information-section.md) 本主题还包括有关入门的信息以及有关先前的 SDK 版本的详细信息。
# 使用 AWS SDK 对 DynamoDB 执行的操作
以下代码示例展示如何使用 AWS SDK 来执行各个 DynamoDB 操作。每个示例都包含一个指向 GitHub 的链接，您可以在其中找到有关设置和运行代码的说明。
这些代码节选调用了 DynamoDB API，是必须在上下文中运行的较大型程序的代码节选。您可以在[将 DynamoDB 与 AWS SDK 结合使用的场景](service_code_examples_scenarios.md)中结合上下文查看操作。
以下示例仅包括最常用的操作。有关完整列表，请参阅 [Amazon DynamoDB API 参考](https://docs.aws.amazon.com/amazondynamodb/latest/APIReference/Welcome.html)。
**Topics**
+ [`BatchExecuteStatement`](example_dynamodb_BatchExecuteStatement_section.md)
+ [`BatchGetItem`](example_dynamodb_BatchGetItem_section.md)
+ [`BatchWriteItem`](example_dynamodb_BatchWriteItem_section.md)
+ [`CreateTable`](example_dynamodb_CreateTable_section.md)
+ [`DeleteItem`](example_dynamodb_DeleteItem_section.md)
+ [`DeleteTable`](example_dynamodb_DeleteTable_section.md)
+ [`DescribeTable`](example_dynamodb_DescribeTable_section.md)
+ [`DescribeTimeToLive`](example_dynamodb_DescribeTimeToLive_section.md)
+ [`ExecuteStatement`](example_dynamodb_ExecuteStatement_section.md)
+ [`GetItem`](example_dynamodb_GetItem_section.md)
+ [`ListTables`](example_dynamodb_ListTables_section.md)
+ [`PutItem`](example_dynamodb_PutItem_section.md)
+ [`Query`](example_dynamodb_Query_section.md)
+ [`Scan`](example_dynamodb_Scan_section.md)
+ [`UpdateItem`](example_dynamodb_UpdateItem_section.md)
+ [`UpdateTable`](example_dynamodb_UpdateTable_section.md)
+ [`UpdateTimeToLive`](example_dynamodb_UpdateTimeToLive_section.md)
# 将 `BatchExecuteStatement` 和 AWS SDK 搭配使用
以下代码示例演示如何使用 `BatchExecuteStatement`。
操作示例是大型程序的代码摘录，必须在上下文中运行。您可以在以下代码示例中查看此操作的上下文：
+ [使用 PartiQL DELETE 删除数据](example_dynamodb_PartiQLDelete_section.md)
+ [使用 PartiQL INSERT 插入数据](example_dynamodb_PartiQLInsert_section.md)
+ [使用批量 PartIQL 语句查询表](example_dynamodb_Scenario_PartiQLBatch_section.md)
+ [使用 PartiQL SELECT 查询数据](example_dynamodb_PartiQLSelect_section.md)
+ [使用 PartiQL UPDATE 更新数据](example_dynamodb_PartiQLUpdate_section.md)
------
#### [ .NET ]
**适用于 .NET 的 SDK**
查看 GitHub，了解更多信息。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/dotnetv3/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
使用批量 INSERT 语句添加项目。
```
///
/// Inserts movies imported from a JSON file into the movie table by
/// using an Amazon DynamoDB PartiQL INSERT statement.
///
/// The name of the table into which the movie
/// information will be inserted.
/// The name of the JSON file that contains
/// movie information.
/// A Boolean value that indicates the success or failure of
/// the insert operation.
public static async Task InsertMovies(string tableName, string movieFileName)
{
// Get the list of movies from the JSON file.
var movies = ImportMovies(movieFileName);
var success = false;
if (movies is not null)
{
// Insert the movies in a batch using PartiQL. Because the
// batch can contain a maximum of 25 items, insert 25 movies
// at a time.
string insertBatch = $"INSERT INTO {tableName} VALUE {{'title': ?, 'year': ?}}";
var statements = new List();
try
{
for (var indexOffset = 0; indexOffset < 250; indexOffset += 25)
{
for (var i = indexOffset; i < indexOffset + 25; i++)
{
statements.Add(new BatchStatementRequest
{
Statement = insertBatch,
Parameters = new List
{
new AttributeValue { S = movies[i].Title },
new AttributeValue { N = movies[i].Year.ToString() },
},
});
}
var response = await Client.BatchExecuteStatementAsync(new BatchExecuteStatementRequest
{
Statements = statements,
});
// Wait between batches for movies to be successfully added.
System.Threading.Thread.Sleep(3000);
success = response.HttpStatusCode == System.Net.HttpStatusCode.OK;
// Clear the list of statements for the next batch.
statements.Clear();
}
}
catch (AmazonDynamoDBException ex)
{
Console.WriteLine(ex.Message);
}
}
return success;
}
///
/// Loads the contents of a JSON file into a list of movies to be
/// added to the DynamoDB table.
///
/// The full path to the JSON file.
/// A generic list of movie objects.
public static List ImportMovies(string movieFileName)
{
if (!File.Exists(movieFileName))
{
return null!;
}
using var sr = new StreamReader(movieFileName);
string json = sr.ReadToEnd();
var allMovies = JsonConvert.DeserializeObject>(json);
if (allMovies is not null)
{
// Return the first 250 entries.
return allMovies.GetRange(0, 250);
}
else
{
return null!;
}
}
```
使用批量 SELECT 语句获取项目。
```
///
/// Gets movies from the movie table by
/// using an Amazon DynamoDB PartiQL SELECT statement.
///
/// The name of the table.
/// The title of the first movie.
/// The title of the second movie.
/// The year of the first movie.
/// The year of the second movie.
/// True if successful.
public static async Task GetBatch(
string tableName,
string title1,
string title2,
int year1,
int year2)
{
var getBatch = $"SELECT * FROM {tableName} WHERE title = ? AND year = ?";
var statements = new List
{
new BatchStatementRequest
{
Statement = getBatch,
Parameters = new List
{
new AttributeValue { S = title1 },
new AttributeValue { N = year1.ToString() },
},
},
new BatchStatementRequest
{
Statement = getBatch,
Parameters = new List
{
new AttributeValue { S = title2 },
new AttributeValue { N = year2.ToString() },
},
}
};
var response = await Client.BatchExecuteStatementAsync(new BatchExecuteStatementRequest
{
Statements = statements,
});
if (response.Responses.Count > 0)
{
response.Responses.ForEach(r =>
{
if (r.Item.Any())
{
Console.WriteLine($"{r.Item["title"]}\t{r.Item["year"]}");
}
});
return true;
}
else
{
Console.WriteLine($"Couldn't find either {title1} or {title2}.");
return false;
}
}
```
使用批量 UPDATE 语句更新项目。
```
///
/// Updates information for multiple movies.
///
/// The name of the table containing the
/// movies to be updated.
/// The producer name for the first movie
/// to update.
/// The title of the first movie.
/// The year that the first movie was released.
/// The producer name for the second
/// movie to update.
/// The title of the second movie.
/// The year that the second movie was released.
/// A Boolean value that indicates the success of the update.
public static async Task UpdateBatch(
string tableName,
string producer1,
string title1,
int year1,
string producer2,
string title2,
int year2)
{
string updateBatch = $"UPDATE {tableName} SET Producer=? WHERE title = ? AND year = ?";
var statements = new List
{
new BatchStatementRequest
{
Statement = updateBatch,
Parameters = new List
{
new AttributeValue { S = producer1 },
new AttributeValue { S = title1 },
new AttributeValue { N = year1.ToString() },
},
},
new BatchStatementRequest
{
Statement = updateBatch,
Parameters = new List
{
new AttributeValue { S = producer2 },
new AttributeValue { S = title2 },
new AttributeValue { N = year2.ToString() },
},
}
};
var response = await Client.BatchExecuteStatementAsync(new BatchExecuteStatementRequest
{
Statements = statements,
});
return response.HttpStatusCode == System.Net.HttpStatusCode.OK;
}
```
使用批量 DELETE 语句删除项目。
```
///
/// Deletes multiple movies using a PartiQL BatchExecuteAsync
/// statement.
///
/// The name of the table containing the
/// moves that will be deleted.
/// The title of the first movie.
/// The year the first movie was released.
/// The title of the second movie.
/// The year the second movie was released.
/// A Boolean value indicating the success of the operation.
public static async Task DeleteBatch(
string tableName,
string title1,
int year1,
string title2,
int year2)
{
string updateBatch = $"DELETE FROM {tableName} WHERE title = ? AND year = ?";
var statements = new List
{
new BatchStatementRequest
{
Statement = updateBatch,
Parameters = new List
{
new AttributeValue { S = title1 },
new AttributeValue { N = year1.ToString() },
},
},
new BatchStatementRequest
{
Statement = updateBatch,
Parameters = new List
{
new AttributeValue { S = title2 },
new AttributeValue { N = year2.ToString() },
},
}
};
var response = await Client.BatchExecuteStatementAsync(new BatchExecuteStatementRequest
{
Statements = statements,
});
return response.HttpStatusCode == System.Net.HttpStatusCode.OK;
}
```
+ 有关 API 详细信息，请参阅《适用于 .NET 的 AWS SDK API Reference》**中的 [BatchExecuteStatement](https://docs.aws.amazon.com/goto/DotNetSDKV3/dynamodb-2012-08-10/BatchExecuteStatement)。
------
#### [ C\$1\$1 ]
**SDK for C\$1\$1**
查看 GitHub，了解更多信息。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/cpp/example_code/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
使用批量 INSERT 语句添加项目。
```
// 2. Add multiple movies using "Insert" statements. (BatchExecuteStatement)
Aws::DynamoDB::DynamoDBClient dynamoClient(clientConfiguration);
std::vector titles;
std::vector ratings;
std::vector years;
std::vector plots;
Aws::String doAgain = "n";
do {
Aws::String aTitle = askQuestion(
"Enter the title of a movie you want to add to the table: ");
titles.push_back(aTitle);
int aYear = askQuestionForInt("What year was it released? ");
years.push_back(aYear);
float aRating = askQuestionForFloatRange(
"On a scale of 1 - 10, how do you rate it? ",
1, 10);
ratings.push_back(aRating);
Aws::String aPlot = askQuestion("Summarize the plot for me: ");
plots.push_back(aPlot);
doAgain = askQuestion(Aws::String("Would you like to add more movies? (y/n) "));
} while (doAgain == "y");
std::cout << "Adding " << titles.size()
<< (titles.size() == 1 ? " movie " : " movies ")
<< "to the table using a batch \"INSERT\" statement." << std::endl;
{
Aws::Vector statements(
titles.size());
std::stringstream sqlStream;
sqlStream << "INSERT INTO \"" << MOVIE_TABLE_NAME << "\" VALUE {'"
<< TITLE_KEY << "': ?, '" << YEAR_KEY << "': ?, '"
<< INFO_KEY << "': ?}";
std::string sql(sqlStream.str());
for (size_t i = 0; i < statements.size(); ++i) {
statements[i].SetStatement(sql);
Aws::Vector attributes;
attributes.push_back(
Aws::DynamoDB::Model::AttributeValue().SetS(titles[i]));
attributes.push_back(Aws::DynamoDB::Model::AttributeValue().SetN(years[i]));
// Create attribute for the info map.
Aws::DynamoDB::Model::AttributeValue infoMapAttribute;
std::shared_ptr ratingAttribute = Aws::MakeShared(
ALLOCATION_TAG.c_str());
ratingAttribute->SetN(ratings[i]);
infoMapAttribute.AddMEntry(RATING_KEY, ratingAttribute);
std::shared_ptr plotAttribute = Aws::MakeShared(
ALLOCATION_TAG.c_str());
plotAttribute->SetS(plots[i]);
infoMapAttribute.AddMEntry(PLOT_KEY, plotAttribute);
attributes.push_back(infoMapAttribute);
statements[i].SetParameters(attributes);
}
Aws::DynamoDB::Model::BatchExecuteStatementRequest request;
request.SetStatements(statements);
Aws::DynamoDB::Model::BatchExecuteStatementOutcome outcome = dynamoClient.BatchExecuteStatement(
request);
if (!outcome.IsSuccess()) {
std::cerr << "Failed to add the movies: " << outcome.GetError().GetMessage()
<< std::endl;
return false;
}
}
```
使用批量 SELECT 语句获取项目。
```
// 3. Get the data for multiple movies using "Select" statements. (BatchExecuteStatement)
{
Aws::Vector statements(
titles.size());
std::stringstream sqlStream;
sqlStream << "SELECT * FROM \"" << MOVIE_TABLE_NAME << "\" WHERE "
<< TITLE_KEY << "=? and " << YEAR_KEY << "=?";
std::string sql(sqlStream.str());
for (size_t i = 0; i < statements.size(); ++i) {
statements[i].SetStatement(sql);
Aws::Vector attributes;
attributes.push_back(
Aws::DynamoDB::Model::AttributeValue().SetS(titles[i]));
attributes.push_back(Aws::DynamoDB::Model::AttributeValue().SetN(years[i]));
statements[i].SetParameters(attributes);
}
Aws::DynamoDB::Model::BatchExecuteStatementRequest request;
request.SetStatements(statements);
Aws::DynamoDB::Model::BatchExecuteStatementOutcome outcome = dynamoClient.BatchExecuteStatement(
request);
if (outcome.IsSuccess()) {
const Aws::DynamoDB::Model::BatchExecuteStatementResult &result = outcome.GetResult();
const Aws::Vector &responses = result.GetResponses();
for (const Aws::DynamoDB::Model::BatchStatementResponse &response: responses) {
const Aws::Map &item = response.GetItem();
printMovieInfo(item);
}
}
else {
std::cerr << "Failed to retrieve the movie information: "
<< outcome.GetError().GetMessage() << std::endl;
return false;
}
}
```
使用批量 UPDATE 语句更新项目。
```
// 4. Update the data for multiple movies using "Update" statements. (BatchExecuteStatement)
for (size_t i = 0; i < titles.size(); ++i) {
ratings[i] = askQuestionForFloatRange(
Aws::String("\nLet's update your the movie, \"") + titles[i] +
".\nYou rated it " + std::to_string(ratings[i])
+ ", what new rating would you give it? ", 1, 10);
}
std::cout << "Updating the movie with a batch \"UPDATE\" statement." << std::endl;
{
Aws::Vector statements(
titles.size());
std::stringstream sqlStream;
sqlStream << "UPDATE \"" << MOVIE_TABLE_NAME << "\" SET "
<< INFO_KEY << "." << RATING_KEY << "=? WHERE "
<< TITLE_KEY << "=? AND " << YEAR_KEY << "=?";
std::string sql(sqlStream.str());
for (size_t i = 0; i < statements.size(); ++i) {
statements[i].SetStatement(sql);
Aws::Vector attributes;
attributes.push_back(
Aws::DynamoDB::Model::AttributeValue().SetN(ratings[i]));
attributes.push_back(
Aws::DynamoDB::Model::AttributeValue().SetS(titles[i]));
attributes.push_back(Aws::DynamoDB::Model::AttributeValue().SetN(years[i]));
statements[i].SetParameters(attributes);
}
Aws::DynamoDB::Model::BatchExecuteStatementRequest request;
request.SetStatements(statements);
Aws::DynamoDB::Model::BatchExecuteStatementOutcome outcome = dynamoClient.BatchExecuteStatement(
request);
if (!outcome.IsSuccess()) {
std::cerr << "Failed to update movie information: "
<< outcome.GetError().GetMessage() << std::endl;
return false;
}
}
```
使用批量 DELETE 语句删除项目。
```
// 6. Delete multiple movies using "Delete" statements. (BatchExecuteStatement)
{
Aws::Vector statements(
titles.size());
std::stringstream sqlStream;
sqlStream << "DELETE FROM \"" << MOVIE_TABLE_NAME << "\" WHERE "
<< TITLE_KEY << "=? and " << YEAR_KEY << "=?";
std::string sql(sqlStream.str());
for (size_t i = 0; i < statements.size(); ++i) {
statements[i].SetStatement(sql);
Aws::Vector attributes;
attributes.push_back(
Aws::DynamoDB::Model::AttributeValue().SetS(titles[i]));
attributes.push_back(Aws::DynamoDB::Model::AttributeValue().SetN(years[i]));
statements[i].SetParameters(attributes);
}
Aws::DynamoDB::Model::BatchExecuteStatementRequest request;
request.SetStatements(statements);
Aws::DynamoDB::Model::BatchExecuteStatementOutcome outcome = dynamoClient.BatchExecuteStatement(
request);
if (!outcome.IsSuccess()) {
std::cerr << "Failed to delete the movies: "
<< outcome.GetError().GetMessage() << std::endl;
return false;
}
}
```
+ 有关 API 详细信息，请参阅《适用于 C\$1\$1 的 AWS SDK API Reference》**中的 [BatchExecuteStatement](https://docs.aws.amazon.com/goto/SdkForCpp/dynamodb-2012-08-10/BatchExecuteStatement)。
------
#### [ Go ]
**适用于 Go 的 SDK V2**
查看 GitHub，了解更多信息。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/gov2/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
为示例定义函数接收器结构。
```
import (
"context"
"fmt"
"log"
"github.com/aws/aws-sdk-go-v2/aws"
"github.com/aws/aws-sdk-go-v2/feature/dynamodb/attributevalue"
"github.com/aws/aws-sdk-go-v2/service/dynamodb"
"github.com/aws/aws-sdk-go-v2/service/dynamodb/types"
)
// PartiQLRunner encapsulates the Amazon DynamoDB service actions used in the
// PartiQL examples. It contains a DynamoDB service client that is used to act on the
// specified table.
type PartiQLRunner struct {
DynamoDbClient *dynamodb.Client
TableName string
}
```
使用批量 INSERT 语句添加项目。
```
// AddMovieBatch runs a batch of PartiQL INSERT statements to add multiple movies to the
// DynamoDB table.
func (runner PartiQLRunner) AddMovieBatch(ctx context.Context, movies []Movie) error {
statementRequests := make([]types.BatchStatementRequest, len(movies))
for index, movie := range movies {
params, err := attributevalue.MarshalList([]interface{}{movie.Title, movie.Year, movie.Info})
if err != nil {
panic(err)
}
statementRequests[index] = types.BatchStatementRequest{
Statement: aws.String(fmt.Sprintf(
"INSERT INTO \"%v\" VALUE {'title': ?, 'year': ?, 'info': ?}", runner.TableName)),
Parameters: params,
}
}
_, err := runner.DynamoDbClient.BatchExecuteStatement(ctx, &dynamodb.BatchExecuteStatementInput{
Statements: statementRequests,
})
if err != nil {
log.Printf("Couldn't insert a batch of items with PartiQL. Here's why: %v\n", err)
}
return err
}
```
使用批量 SELECT 语句获取项目。
```
// GetMovieBatch runs a batch of PartiQL SELECT statements to get multiple movies from
// the DynamoDB table by title and year.
func (runner PartiQLRunner) GetMovieBatch(ctx context.Context, movies []Movie) ([]Movie, error) {
statementRequests := make([]types.BatchStatementRequest, len(movies))
for index, movie := range movies {
params, err := attributevalue.MarshalList([]interface{}{movie.Title, movie.Year})
if err != nil {
panic(err)
}
statementRequests[index] = types.BatchStatementRequest{
Statement: aws.String(
fmt.Sprintf("SELECT * FROM \"%v\" WHERE title=? AND year=?", runner.TableName)),
Parameters: params,
}
}
output, err := runner.DynamoDbClient.BatchExecuteStatement(ctx, &dynamodb.BatchExecuteStatementInput{
Statements: statementRequests,
})
var outMovies []Movie
if err != nil {
log.Printf("Couldn't get a batch of items with PartiQL. Here's why: %v\n", err)
} else {
for _, response := range output.Responses {
var movie Movie
err = attributevalue.UnmarshalMap(response.Item, &movie)
if err != nil {
log.Printf("Couldn't unmarshal response. Here's why: %v\n", err)
} else {
outMovies = append(outMovies, movie)
}
}
}
return outMovies, err
}
```
使用批量 UPDATE 语句更新项目。
```
// UpdateMovieBatch runs a batch of PartiQL UPDATE statements to update the rating of
// multiple movies that already exist in the DynamoDB table.
func (runner PartiQLRunner) UpdateMovieBatch(ctx context.Context, movies []Movie, ratings []float64) error {
statementRequests := make([]types.BatchStatementRequest, len(movies))
for index, movie := range movies {
params, err := attributevalue.MarshalList([]interface{}{ratings[index], movie.Title, movie.Year})
if err != nil {
panic(err)
}
statementRequests[index] = types.BatchStatementRequest{
Statement: aws.String(
fmt.Sprintf("UPDATE \"%v\" SET info.rating=? WHERE title=? AND year=?", runner.TableName)),
Parameters: params,
}
}
_, err := runner.DynamoDbClient.BatchExecuteStatement(ctx, &dynamodb.BatchExecuteStatementInput{
Statements: statementRequests,
})
if err != nil {
log.Printf("Couldn't update the batch of movies. Here's why: %v\n", err)
}
return err
}
```
使用批量 DELETE 语句删除项目。
```
// DeleteMovieBatch runs a batch of PartiQL DELETE statements to remove multiple movies
// from the DynamoDB table.
func (runner PartiQLRunner) DeleteMovieBatch(ctx context.Context, movies []Movie) error {
statementRequests := make([]types.BatchStatementRequest, len(movies))
for index, movie := range movies {
params, err := attributevalue.MarshalList([]interface{}{movie.Title, movie.Year})
if err != nil {
panic(err)
}
statementRequests[index] = types.BatchStatementRequest{
Statement: aws.String(
fmt.Sprintf("DELETE FROM \"%v\" WHERE title=? AND year=?", runner.TableName)),
Parameters: params,
}
}
_, err := runner.DynamoDbClient.BatchExecuteStatement(ctx, &dynamodb.BatchExecuteStatementInput{
Statements: statementRequests,
})
if err != nil {
log.Printf("Couldn't delete the batch of movies. Here's why: %v\n", err)
}
return err
}
```
定义本示例中使用的 Movie 结构。
```
import (
"archive/zip"
"bytes"
"encoding/json"
"fmt"
"io"
"log"
"net/http"
"github.com/aws/aws-sdk-go-v2/feature/dynamodb/attributevalue"
"github.com/aws/aws-sdk-go-v2/service/dynamodb/types"
)
// Movie encapsulates data about a movie. Title and Year are the composite primary key
// of the movie in Amazon DynamoDB. Title is the sort key, Year is the partition key,
// and Info is additional data.
type Movie struct {
Title string `dynamodbav:"title"`
Year int `dynamodbav:"year"`
Info map[string]interface{} `dynamodbav:"info"`
}
// GetKey returns the composite primary key of the movie in a format that can be
// sent to DynamoDB.
func (movie Movie) GetKey() map[string]types.AttributeValue {
title, err := attributevalue.Marshal(movie.Title)
if err != nil {
panic(err)
}
year, err := attributevalue.Marshal(movie.Year)
if err != nil {
panic(err)
}
return map[string]types.AttributeValue{"title": title, "year": year}
}
// String returns the title, year, rating, and plot of a movie, formatted for the example.
func (movie Movie) String() string {
return fmt.Sprintf("%v\n\tReleased: %v\n\tRating: %v\n\tPlot: %v\n",
movie.Title, movie.Year, movie.Info["rating"], movie.Info["plot"])
}
```
+ 有关 API 详细信息，请参阅《适用于 Go 的 AWS SDK API Reference》**中的 [BatchExecuteStatement](https://pkg.go.dev/github.com/aws/aws-sdk-go-v2/service/dynamodb#Client.BatchExecuteStatement)。
------
#### [ JavaScript ]
**SDK for JavaScript (v3)**
查看 GitHub，了解更多信息。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javascriptv3/example_code/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
使用 PartiQL 创建一批项目。
```
import { DynamoDBClient } from "@aws-sdk/client-dynamodb";
import {
DynamoDBDocumentClient,
BatchExecuteStatementCommand,
} from "@aws-sdk/lib-dynamodb";
const client = new DynamoDBClient({});
const docClient = DynamoDBDocumentClient.from(client);
export const main = async () => {
const breakfastFoods = ["Eggs", "Bacon", "Sausage"];
const command = new BatchExecuteStatementCommand({
Statements: breakfastFoods.map((food) => ({
Statement: `INSERT INTO BreakfastFoods value {'Name':?}`,
Parameters: [food],
})),
});
const response = await docClient.send(command);
console.log(response);
return response;
};
```
使用 PartiQL 获取一批项目。
```
import { DynamoDBClient } from "@aws-sdk/client-dynamodb";
import {
DynamoDBDocumentClient,
BatchExecuteStatementCommand,
} from "@aws-sdk/lib-dynamodb";
const client = new DynamoDBClient({});
const docClient = DynamoDBDocumentClient.from(client);
export const main = async () => {
const command = new BatchExecuteStatementCommand({
Statements: [
{
Statement: "SELECT * FROM PepperMeasurements WHERE Unit=?",
Parameters: ["Teaspoons"],
ConsistentRead: true,
},
{
Statement: "SELECT * FROM PepperMeasurements WHERE Unit=?",
Parameters: ["Grams"],
ConsistentRead: true,
},
],
});
const response = await docClient.send(command);
console.log(response);
return response;
};
```
使用 PartiQL 更新一批项目。
```
import { DynamoDBClient } from "@aws-sdk/client-dynamodb";
import {
DynamoDBDocumentClient,
BatchExecuteStatementCommand,
} from "@aws-sdk/lib-dynamodb";
const client = new DynamoDBClient({});
const docClient = DynamoDBDocumentClient.from(client);
export const main = async () => {
const eggUpdates = [
["duck", "fried"],
["chicken", "omelette"],
];
const command = new BatchExecuteStatementCommand({
Statements: eggUpdates.map((change) => ({
Statement: "UPDATE Eggs SET Style=? where Variety=?",
Parameters: [change[1], change[0]],
})),
});
const response = await docClient.send(command);
console.log(response);
return response;
};
```
使用 PartiQL 删除一批项目。
```
import { DynamoDBClient } from "@aws-sdk/client-dynamodb";
import {
DynamoDBDocumentClient,
BatchExecuteStatementCommand,
} from "@aws-sdk/lib-dynamodb";
const client = new DynamoDBClient({});
const docClient = DynamoDBDocumentClient.from(client);
export const main = async () => {
const command = new BatchExecuteStatementCommand({
Statements: [
{
Statement: "DELETE FROM Flavors where Name=?",
Parameters: ["Grape"],
},
{
Statement: "DELETE FROM Flavors where Name=?",
Parameters: ["Strawberry"],
},
],
});
const response = await docClient.send(command);
console.log(response);
return response;
};
```
+ 有关 API 详细信息，请参阅《适用于 JavaScript 的 AWS SDK API Reference》**中的 [BatchExecuteStatement](https://docs.aws.amazon.com/AWSJavaScriptSDK/v3/latest/client/dynamodb/command/BatchExecuteStatementCommand)。
------
#### [ PHP ]
**适用于 PHP 的 SDK**
查看 GitHub，了解更多信息。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/php/example_code/dynamodb#code-examples) 中查找完整示例，了解如何进行设置和运行。
```
public function getItemByPartiQLBatch(string $tableName, array $keys): Result
{
$statements = [];
foreach ($keys as $key) {
list($statement, $parameters) = $this->buildStatementAndParameters("SELECT", $tableName, $key['Item']);
$statements[] = [
'Statement' => "$statement",
'Parameters' => $parameters,
];
}
return $this->dynamoDbClient->batchExecuteStatement([
'Statements' => $statements,
]);
}
public function insertItemByPartiQLBatch(string $statement, array $parameters)
{
$this->dynamoDbClient->batchExecuteStatement([
'Statements' => [
[
'Statement' => "$statement",
'Parameters' => $parameters,
],
],
]);
}
public function updateItemByPartiQLBatch(string $statement, array $parameters)
{
$this->dynamoDbClient->batchExecuteStatement([
'Statements' => [
[
'Statement' => "$statement",
'Parameters' => $parameters,
],
],
]);
}
public function deleteItemByPartiQLBatch(string $statement, array $parameters)
{
$this->dynamoDbClient->batchExecuteStatement([
'Statements' => [
[
'Statement' => "$statement",
'Parameters' => $parameters,
],
],
]);
}
```
+ 有关 API 详细信息，请参阅《适用于 PHP 的 AWS SDK API Reference》**中的 [BatchExecuteStatement](https://docs.aws.amazon.com/goto/SdkForPHPV3/dynamodb-2012-08-10/BatchExecuteStatement)。
------
#### [ Python ]
**适用于 Python 的 SDK（Boto3）**
查看 GitHub，了解更多信息。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/python/example_code/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
```
class PartiQLBatchWrapper:
"""
Encapsulates a DynamoDB resource to run PartiQL statements.
"""
def __init__(self, dyn_resource):
"""
:param dyn_resource: A Boto3 DynamoDB resource.
"""
self.dyn_resource = dyn_resource
def run_partiql(self, statements, param_list):
"""
Runs a PartiQL statement. A Boto3 resource is used even though
`execute_statement` is called on the underlying `client` object because the
resource transforms input and output from plain old Python objects (POPOs) to
the DynamoDB format. If you create the client directly, you must do these
transforms yourself.
:param statements: The batch of PartiQL statements.
:param param_list: The batch of PartiQL parameters that are associated with
each statement. This list must be in the same order as the
statements.
:return: The responses returned from running the statements, if any.
"""
try:
output = self.dyn_resource.meta.client.batch_execute_statement(
Statements=[
{"Statement": statement, "Parameters": params}
for statement, params in zip(statements, param_list)
]
)
except ClientError as err:
if err.response["Error"]["Code"] == "ResourceNotFoundException":
logger.error(
"Couldn't execute batch of PartiQL statements because the table "
"does not exist."
)
else:
logger.error(
"Couldn't execute batch of PartiQL statements. Here's why: %s: %s",
err.response["Error"]["Code"],
err.response["Error"]["Message"],
)
raise
else:
return output
```
+ 有关 API 详细信息，请参阅《AWS SDK for Python (Boto3) API Reference》**中的 [BatchExecuteStatement](https://docs.aws.amazon.com/goto/boto3/dynamodb-2012-08-10/BatchExecuteStatement)。
------
#### [ Ruby ]
**适用于 Ruby 的 SDK**
查看 GitHub，了解更多信息。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/ruby/example_code/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
使用 PartiQL 读取一批项目。
```
class DynamoDBPartiQLBatch
attr_reader :dynamo_resource, :table
def initialize(table_name)
client = Aws::DynamoDB::Client.new(region: 'us-east-1')
@dynamodb = Aws::DynamoDB::Resource.new(client: client)
@table = @dynamodb.table(table_name)
end
# Selects a batch of items from a table using PartiQL
#
# @param batch_titles [Array] Collection of movie titles
# @return [Aws::DynamoDB::Types::BatchExecuteStatementOutput]
def batch_execute_select(batch_titles)
request_items = batch_titles.map do |title, year|
{
statement: "SELECT * FROM \"#{@table.name}\" WHERE title=? and year=?",
parameters: [title, year]
}
end
@dynamodb.client.batch_execute_statement({ statements: request_items })
end
```
使用 PartiQL 删除一批项目。
```
class DynamoDBPartiQLBatch
attr_reader :dynamo_resource, :table
def initialize(table_name)
client = Aws::DynamoDB::Client.new(region: 'us-east-1')
@dynamodb = Aws::DynamoDB::Resource.new(client: client)
@table = @dynamodb.table(table_name)
end
# Deletes a batch of items from a table using PartiQL
#
# @param batch_titles [Array] Collection of movie titles
# @return [Aws::DynamoDB::Types::BatchExecuteStatementOutput]
def batch_execute_write(batch_titles)
request_items = batch_titles.map do |title, year|
{
statement: "DELETE FROM \"#{@table.name}\" WHERE title=? and year=?",
parameters: [title, year]
}
end
@dynamodb.client.batch_execute_statement({ statements: request_items })
end
```
+ 有关 API 详细信息，请参阅《适用于 Ruby 的 AWS SDK API Reference》**中的 [BatchExecuteStatement](https://docs.aws.amazon.com/goto/SdkForRubyV3/dynamodb-2012-08-10/BatchExecuteStatement)。
------
有关 AWS SDK 开发人员指南和代码示例的完整列表，请参阅 [结合使用 DynamoDB 与 AWS SDK](sdk-general-information-section.md) 本主题还包括有关入门的信息以及有关先前的 SDK 版本的详细信息。
# 将 `BatchGetItem` 与 AWS SDK 或 CLI 配合使用
以下代码示例演示如何使用 `BatchGetItem`。
------
#### [ .NET ]
**适用于 .NET 的 SDK**
查看 GitHub，了解更多信息。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/dotnetv3/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
```
using System;
using System.Collections.Generic;
using Amazon.DynamoDBv2;
using Amazon.DynamoDBv2.Model;
namespace LowLevelBatchGet
{
public class LowLevelBatchGet
{
private static readonly string _table1Name = "Forum";
private static readonly string _table2Name = "Thread";
public static async void RetrieveMultipleItemsBatchGet(AmazonDynamoDBClient client)
{
var request = new BatchGetItemRequest
{
RequestItems = new Dictionary()
{
{ _table1Name,
new KeysAndAttributes
{
Keys = new List >()
{
new Dictionary()
{
{ "Name", new AttributeValue {
S = "Amazon DynamoDB"
} }
},
new Dictionary()
{
{ "Name", new AttributeValue {
S = "Amazon S3"
} }
}
}
}},
{
_table2Name,
new KeysAndAttributes
{
Keys = new List >()
{
new Dictionary()
{
{ "ForumName", new AttributeValue {
S = "Amazon DynamoDB"
} },
{ "Subject", new AttributeValue {
S = "DynamoDB Thread 1"
} }
},
new Dictionary()
{
{ "ForumName", new AttributeValue {
S = "Amazon DynamoDB"
} },
{ "Subject", new AttributeValue {
S = "DynamoDB Thread 2"
} }
},
new Dictionary()
{
{ "ForumName", new AttributeValue {
S = "Amazon S3"
} },
{ "Subject", new AttributeValue {
S = "S3 Thread 1"
} }
}
}
}
}
}
};
BatchGetItemResponse response;
do
{
Console.WriteLine("Making request");
response = await client.BatchGetItemAsync(request);
// Check the response.
var responses = response.Responses; // Attribute list in the response.
foreach (var tableResponse in responses)
{
var tableResults = tableResponse.Value;
Console.WriteLine("Items retrieved from table {0}", tableResponse.Key);
foreach (var item1 in tableResults)
{
PrintItem(item1);
}
}
// Any unprocessed keys? could happen if you exceed ProvisionedThroughput or some other error.
Dictionary unprocessedKeys = response.UnprocessedKeys;
foreach (var unprocessedTableKeys in unprocessedKeys)
{
// Print table name.
Console.WriteLine(unprocessedTableKeys.Key);
// Print unprocessed primary keys.
foreach (var key in unprocessedTableKeys.Value.Keys)
{
PrintItem(key);
}
}
request.RequestItems = unprocessedKeys;
} while (response.UnprocessedKeys.Count > 0);
}
private static void PrintItem(Dictionary attributeList)
{
foreach (KeyValuePair kvp in attributeList)
{
string attributeName = kvp.Key;
AttributeValue value = kvp.Value;
Console.WriteLine(
attributeName + " " +
(value.S == null ? "" : "S=[" + value.S + "]") +
(value.N == null ? "" : "N=[" + value.N + "]") +
(value.SS == null ? "" : "SS=[" + string.Join(",", value.SS.ToArray()) + "]") +
(value.NS == null ? "" : "NS=[" + string.Join(",", value.NS.ToArray()) + "]")
);
}
Console.WriteLine("************************************************");
}
static void Main()
{
var client = new AmazonDynamoDBClient();
RetrieveMultipleItemsBatchGet(client);
}
}
}
```
+ 有关 API 详细信息，请参阅《适用于 .NET 的 AWS SDK API Reference》**中的 [BatchGetItem](https://docs.aws.amazon.com/goto/DotNetSDKV3/dynamodb-2012-08-10/BatchGetItem)。
------
#### [ Bash ]
**AWS CLI 及 Bash 脚本**
查看 GitHub，了解更多信息。查找完整示例，了解如何在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/aws-cli/bash-linux/dynamodb#code-examples)中进行设置和运行。
```
#############################################################################
# function dynamodb_batch_get_item
#
# This function gets a batch of items from a DynamoDB table.
#
# Parameters:
# -i item -- Path to json file containing the keys of the items to get.
#
# Returns:
# The items as json output.
# And:
# 0 - If successful.
# 1 - If it fails.
##########################################################################
function dynamodb_batch_get_item() {
local item response
local option OPTARG # Required to use getopts command in a function.
#######################################
# Function usage explanation
#######################################
function usage() {
echo "function dynamodb_batch_get_item"
echo "Get a batch of items from a DynamoDB table."
echo " -i item -- Path to json file containing the keys of the items to get."
echo ""
}
while getopts "i:h" option; do
case "${option}" in
i) item="${OPTARG}" ;;
h)
usage
return 0
;;
\?)
echo "Invalid parameter"
usage
return 1
;;
esac
done
export OPTIND=1
if [[ -z "$item" ]]; then
errecho "ERROR: You must provide an item with the -i parameter."
usage
return 1
fi
response=$(aws dynamodb batch-get-item \
--request-items file://"$item")
local error_code=${?}
if [[ $error_code -ne 0 ]]; then
aws_cli_error_log $error_code
errecho "ERROR: AWS reports batch-get-item operation failed.$response"
return 1
fi
echo "$response"
return 0
}
```
本示例中使用的实用程序函数。
```
###############################################################################
# function errecho
#
# This function outputs everything sent to it to STDERR (standard error output).
###############################################################################
function errecho() {
printf "%s\n" "$*" 1>&2
}
##############################################################################
# function aws_cli_error_log()
#
# This function is used to log the error messages from the AWS CLI.
#
# See https://docs.aws.amazon.com/cli/latest/topic/return-codes.html#cli-aws-help-return-codes.
#
# The function expects the following argument:
# $1 - The error code returned by the AWS CLI.
#
# Returns:
# 0: - Success.
#
##############################################################################
function aws_cli_error_log() {
local err_code=$1
errecho "Error code : $err_code"
if [ "$err_code" == 1 ]; then
errecho " One or more S3 transfers failed."
elif [ "$err_code" == 2 ]; then
errecho " Command line failed to parse."
elif [ "$err_code" == 130 ]; then
errecho " Process received SIGINT."
elif [ "$err_code" == 252 ]; then
errecho " Command syntax invalid."
elif [ "$err_code" == 253 ]; then
errecho " The system environment or configuration was invalid."
elif [ "$err_code" == 254 ]; then
errecho " The service returned an error."
elif [ "$err_code" == 255 ]; then
errecho " 255 is a catch-all error."
fi
return 0
}
```
+ 有关 API 详细信息，请参阅《AWS CLI 命令参考》**中的 [BatchGetItem](https://docs.aws.amazon.com/goto/aws-cli/dynamodb-2012-08-10/BatchGetItem)。
------
#### [ C\$1\$1 ]
**SDK for C\$1\$1**
查看 GitHub，了解更多信息。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/cpp/example_code/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
```
//! Batch get items from different Amazon DynamoDB tables.
/*!
\sa batchGetItem()
\param clientConfiguration: AWS client configuration.
\return bool: Function succeeded.
*/
bool AwsDoc::DynamoDB::batchGetItem(
const Aws::Client::ClientConfiguration &clientConfiguration) {
Aws::DynamoDB::DynamoDBClient dynamoClient(clientConfiguration);
Aws::DynamoDB::Model::BatchGetItemRequest request;
// Table1: Forum.
Aws::String table1Name = "Forum";
Aws::DynamoDB::Model::KeysAndAttributes table1KeysAndAttributes;
// Table1: Projection expression.
table1KeysAndAttributes.SetProjectionExpression("#n, Category, Messages, #v");
// Table1: Expression attribute names.
Aws::Http::HeaderValueCollection headerValueCollection;
headerValueCollection.emplace("#n", "Name");
headerValueCollection.emplace("#v", "Views");
table1KeysAndAttributes.SetExpressionAttributeNames(headerValueCollection);
// Table1: Set key name, type, and value to search.
std::vector nameValues = {"Amazon DynamoDB", "Amazon S3"};
for (const Aws::String &name: nameValues) {
Aws::Map keys;
Aws::DynamoDB::Model::AttributeValue key;
key.SetS(name);
keys.emplace("Name", key);
table1KeysAndAttributes.AddKeys(keys);
}
Aws::Map requestItems;
requestItems.emplace(table1Name, table1KeysAndAttributes);
// Table2: ProductCatalog.
Aws::String table2Name = "ProductCatalog";
Aws::DynamoDB::Model::KeysAndAttributes table2KeysAndAttributes;
table2KeysAndAttributes.SetProjectionExpression("Title, Price, Color");
// Table2: Set key name, type, and value to search.
std::vector idValues = {"102", "103", "201"};
for (const Aws::String &id: idValues) {
Aws::Map keys;
Aws::DynamoDB::Model::AttributeValue key;
key.SetN(id);
keys.emplace("Id", key);
table2KeysAndAttributes.AddKeys(keys);
}
requestItems.emplace(table2Name, table2KeysAndAttributes);
bool result = true;
do { // Use a do loop to handle pagination.
request.SetRequestItems(requestItems);
const Aws::DynamoDB::Model::BatchGetItemOutcome &outcome = dynamoClient.BatchGetItem(
request);
if (outcome.IsSuccess()) {
for (const auto &responsesMapEntry: outcome.GetResult().GetResponses()) {
Aws::String tableName = responsesMapEntry.first;
const Aws::Vector> &tableResults = responsesMapEntry.second;
std::cout << "Retrieved " << tableResults.size()
<< " responses for table '" << tableName << "'.\n"
<< std::endl;
if (tableName == "Forum") {
std::cout << "Name | Category | Message | Views" << std::endl;
for (const Aws::Map &item: tableResults) {
std::cout << item.at("Name").GetS() << " | ";
std::cout << item.at("Category").GetS() << " | ";
std::cout << (item.count("Message") == 0 ? "" : item.at(
"Messages").GetN()) << " | ";
std::cout << (item.count("Views") == 0 ? "" : item.at(
"Views").GetN()) << std::endl;
}
}
else {
std::cout << "Title | Price | Color" << std::endl;
for (const Aws::Map &item: tableResults) {
std::cout << item.at("Title").GetS() << " | ";
std::cout << (item.count("Price") == 0 ? "" : item.at(
"Price").GetN());
if (item.count("Color")) {
std::cout << " | ";
for (const std::shared_ptr &listItem: item.at(
"Color").GetL())
std::cout << listItem->GetS() << " ";
}
std::cout << std::endl;
}
}
std::cout << std::endl;
}
// If necessary, repeat request for remaining items.
requestItems = outcome.GetResult().GetUnprocessedKeys();
}
else {
std::cerr << "Batch get item failed: " << outcome.GetError().GetMessage()
<< std::endl;
result = false;
break;
}
} while (!requestItems.empty());
return result;
}
```
+ 有关 API 详细信息，请参阅《适用于 C\$1\$1 的 AWS SDK API Reference》**中的 [BatchGetItem](https://docs.aws.amazon.com/goto/SdkForCpp/dynamodb-2012-08-10/BatchGetItem)。
------
#### [ CLI ]
**AWS CLI**
**检索表中的多个项**
以下 `batch-get-items` 示例使用一批三个 `GetItem` 请求从 `MusicCollection` 表中读取多个项，并请求该操作所用的读取容量单位数。该命令仅返回 `AlbumTitle` 属性。
```
aws dynamodb batch-get-item \
--request-items file://request-items.json \
--return-consumed-capacity TOTAL
```
的内容`request-items.json`：
```
{
"MusicCollection": {
"Keys": [
{
"Artist": {"S": "No One You Know"},
"SongTitle": {"S": "Call Me Today"}
},
{
"Artist": {"S": "Acme Band"},
"SongTitle": {"S": "Happy Day"}
},
{
"Artist": {"S": "No One You Know"},
"SongTitle": {"S": "Scared of My Shadow"}
}
],
"ProjectionExpression":"AlbumTitle"
}
}
```
输出：
```
{
"Responses": {
"MusicCollection": [
{
"AlbumTitle": {
"S": "Somewhat Famous"
}
},
{
"AlbumTitle": {
"S": "Blue Sky Blues"
}
},
{
"AlbumTitle": {
"S": "Louder Than Ever"
}
}
]
},
"UnprocessedKeys": {},
"ConsumedCapacity": [
{
"TableName": "MusicCollection",
"CapacityUnits": 1.5
}
]
}
```
有关更多信息，请参阅《Amazon DynamoDB 开发人员指南》**中的[批量操作](https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/WorkingWithItems.html#WorkingWithItems.BatchOperations)。
+ 有关 API 详细信息，请参阅《AWS CLI 命令参考》**中的 [BatchGetItem](https://awscli.amazonaws.com/v2/documentation/api/latest/reference/dynamodb/batch-get-item.html)。
------
#### [ Java ]
**适用于 Java 的 SDK 2.x**
查看 GitHub，了解更多信息。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javav2/example_code/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
展示如何使用服务客户端获取批量项目。
```
import software.amazon.awssdk.regions.Region;
import software.amazon.awssdk.services.dynamodb.DynamoDbClient;
import software.amazon.awssdk.services.dynamodb.model.AttributeValue;
import software.amazon.awssdk.services.dynamodb.model.BatchGetItemRequest;
import software.amazon.awssdk.services.dynamodb.model.BatchGetItemResponse;
import software.amazon.awssdk.services.dynamodb.model.KeysAndAttributes;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
/**
* Before running this Java V2 code example, set up your development environment, including your credentials.
*
* For more information, see the following documentation topic:
*
* https://docs.aws.amazon.com/sdk-for-java/latest/developer-guide/get-started.html
*/
public class BatchReadItems {
public static void main(String[] args){
final String usage = """
Usage:
Where:
tableName - The Amazon DynamoDB table (for example, Music).\s
""";
String tableName = "Music";
Region region = Region.US_EAST_1;
DynamoDbClient dynamoDbClient = DynamoDbClient.builder()
.region(region)
.build();
getBatchItems(dynamoDbClient, tableName);
}
public static void getBatchItems(DynamoDbClient dynamoDbClient, String tableName) {
// Define the primary key values for the items you want to retrieve.
Map key1 = new HashMap<>();
key1.put("Artist", AttributeValue.builder().s("Artist1").build());
Map key2 = new HashMap<>();
key2.put("Artist", AttributeValue.builder().s("Artist2").build());
// Construct the batchGetItem request.
Map requestItems = new HashMap<>();
requestItems.put(tableName, KeysAndAttributes.builder()
.keys(List.of(key1, key2))
.projectionExpression("Artist, SongTitle")
.build());
BatchGetItemRequest batchGetItemRequest = BatchGetItemRequest.builder()
.requestItems(requestItems)
.build();
// Make the batchGetItem request.
BatchGetItemResponse batchGetItemResponse = dynamoDbClient.batchGetItem(batchGetItemRequest);
// Extract and print the retrieved items.
Map>> responses = batchGetItemResponse.responses();
if (responses.containsKey(tableName)) {
List> musicItems = responses.get(tableName);
for (Map item : musicItems) {
System.out.println("Artist: " + item.get("Artist").s() +
", SongTitle: " + item.get("SongTitle").s());
}
} else {
System.out.println("No items retrieved.");
}
}
}
```
展示如何使用服务客户端和分页器获取批量项目。
```
import software.amazon.awssdk.regions.Region;
import software.amazon.awssdk.services.dynamodb.DynamoDbClient;
import software.amazon.awssdk.services.dynamodb.model.AttributeValue;
import software.amazon.awssdk.services.dynamodb.model.BatchGetItemRequest;
import software.amazon.awssdk.services.dynamodb.model.KeysAndAttributes;
import java.util.Collections;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
public class BatchGetItemsPaginator {
public static void main(String[] args){
final String usage = """
Usage:
Where:
tableName - The Amazon DynamoDB table (for example, Music).\s
""";
String tableName = "Music";
Region region = Region.US_EAST_1;
DynamoDbClient dynamoDbClient = DynamoDbClient.builder()
.region(region)
.build();
getBatchItemsPaginator(dynamoDbClient, tableName) ;
}
public static void getBatchItemsPaginator(DynamoDbClient dynamoDbClient, String tableName) {
// Define the primary key values for the items you want to retrieve.
Map key1 = new HashMap<>();
key1.put("Artist", AttributeValue.builder().s("Artist1").build());
Map key2 = new HashMap<>();
key2.put("Artist", AttributeValue.builder().s("Artist2").build());
// Construct the batchGetItem request.
Map requestItems = new HashMap<>();
requestItems.put(tableName, KeysAndAttributes.builder()
.keys(List.of(key1, key2))
.projectionExpression("Artist, SongTitle")
.build());
BatchGetItemRequest batchGetItemRequest = BatchGetItemRequest.builder()
.requestItems(requestItems)
.build();
// Use batchGetItemPaginator for paginated requests.
dynamoDbClient.batchGetItemPaginator(batchGetItemRequest).stream()
.flatMap(response -> response.responses().getOrDefault(tableName, Collections.emptyList()).stream())
.forEach(item -> {
System.out.println("Artist: " + item.get("Artist").s() +
", SongTitle: " + item.get("SongTitle").s());
});
}
}
```
+ 有关 API 详细信息，请参阅《AWS SDK for Java 2.x API Reference》**中的 [BatchGetItem](https://docs.aws.amazon.com/goto/SdkForJavaV2/dynamodb-2012-08-10/BatchGetItem)。
------
#### [ JavaScript ]
**SDK for JavaScript (v3)**
查看 GitHub，了解更多信息。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javascriptv3/example_code/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
此示例使用文档客户端来简化在 DynamoDB 中处理项目的过程。有关 API 详细信息，请参阅 [BatchGet](https://docs.aws.amazon.com/AWSJavaScriptSDK/v3/latest/Package/-aws-sdk-lib-dynamodb/Class/BatchGetCommand/)。
```
import { DynamoDBClient } from "@aws-sdk/client-dynamodb";
import { BatchGetCommand, DynamoDBDocumentClient } from "@aws-sdk/lib-dynamodb";
const client = new DynamoDBClient({});
const docClient = DynamoDBDocumentClient.from(client);
export const main = async () => {
const command = new BatchGetCommand({
// Each key in this object is the name of a table. This example refers
// to a Books table.
RequestItems: {
Books: {
// Each entry in Keys is an object that specifies a primary key.
Keys: [
{
Title: "How to AWS",
},
{
Title: "DynamoDB for DBAs",
},
],
// Only return the "Title" and "PageCount" attributes.
ProjectionExpression: "Title, PageCount",
},
},
});
const response = await docClient.send(command);
console.log(response.Responses.Books);
return response;
};
```
+ 有关更多信息，请参阅《适用于 JavaScript 的 AWS SDK 开发人员指南》[https://docs.aws.amazon.com/sdk-for-javascript/v3/developer-guide/dynamodb-example-table-read-write-batch.html#dynamodb-example-table-read-write-batch-reading](https://docs.aws.amazon.com/sdk-for-javascript/v3/developer-guide/dynamodb-example-table-read-write-batch.html#dynamodb-example-table-read-write-batch-reading)。
+ 有关 API 详细信息，请参阅《适用于 JavaScript 的 AWS SDK API Reference》**中的 [BatchGetItem](https://docs.aws.amazon.com/AWSJavaScriptSDK/v3/latest/client/dynamodb/command/BatchGetItemCommand)。
**适用于 JavaScript 的 SDK（v2）**
查看 GitHub，了解更多信息。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javascript/example_code/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
```
// Load the AWS SDK for Node.js
var AWS = require("aws-sdk");
// Set the region
AWS.config.update({ region: "REGION" });
// Create DynamoDB service object
var ddb = new AWS.DynamoDB({ apiVersion: "2012-08-10" });
var params = {
RequestItems: {
TABLE_NAME: {
Keys: [
{ KEY_NAME: { N: "KEY_VALUE_1" } },
{ KEY_NAME: { N: "KEY_VALUE_2" } },
{ KEY_NAME: { N: "KEY_VALUE_3" } },
],
ProjectionExpression: "KEY_NAME, ATTRIBUTE",
},
},
};
ddb.batchGetItem(params, function (err, data) {
if (err) {
console.log("Error", err);
} else {
data.Responses.TABLE_NAME.forEach(function (element, index, array) {
console.log(element);
});
}
});
```
+ 有关更多信息，请参阅《适用于 JavaScript 的 AWS SDK 开发人员指南》[https://docs.aws.amazon.com/sdk-for-javascript/v2/developer-guide/dynamodb-example-table-read-write-batch.html#dynamodb-example-table-read-write-batch-reading](https://docs.aws.amazon.com/sdk-for-javascript/v2/developer-guide/dynamodb-example-table-read-write-batch.html#dynamodb-example-table-read-write-batch-reading)。
+ 有关 API 详细信息，请参阅《适用于 JavaScript 的 AWS SDK API Reference》**中的 [BatchGetItem](https://docs.aws.amazon.com/goto/AWSJavaScriptSDK/dynamodb-2012-08-10/BatchGetItem)。
------
#### [ PowerShell ]
**适用于 PowerShell V4 的工具**
**示例 1：从 DynamoDB 表“Music”和“Songs”中获取 SongTitle 为“Somewhere Down The Road”的项目。**
```
$key = @{
SongTitle = 'Somewhere Down The Road'
Artist = 'No One You Know'
} | ConvertTo-DDBItem
$keysAndAttributes = New-Object Amazon.DynamoDBv2.Model.KeysAndAttributes
$list = New-Object 'System.Collections.Generic.List[System.Collections.Generic.Dictionary[String, Amazon.DynamoDBv2.Model.AttributeValue]]'
$list.Add($key)
$keysAndAttributes.Keys = $list
$requestItem = @{
'Music' = [Amazon.DynamoDBv2.Model.KeysAndAttributes]$keysAndAttributes
'Songs' = [Amazon.DynamoDBv2.Model.KeysAndAttributes]$keysAndAttributes
}
$batchItems = Get-DDBBatchItem -RequestItem $requestItem
$batchItems.GetEnumerator() | ForEach-Object {$PSItem.Value} | ConvertFrom-DDBItem
```
**输出：**
```
Name Value
---- -----
Artist No One You Know
SongTitle Somewhere Down The Road
AlbumTitle Somewhat Famous
CriticRating 10
Genre Country
Price 1.94
Artist No One You Know
SongTitle Somewhere Down The Road
AlbumTitle Somewhat Famous
CriticRating 10
Genre Country
Price 1.94
```
+ 有关 API 详细信息，请参阅《AWS Tools for PowerShell Cmdlet Reference (V4)》**中的 [BatchGetItem](https://docs.aws.amazon.com/powershell/v4/reference)。
**适用于 PowerShell V5 的工具**
**示例 1：从 DynamoDB 表“Music”和“Songs”中获取 SongTitle 为“Somewhere Down The Road”的项目。**
```
$key = @{
SongTitle = 'Somewhere Down The Road'
Artist = 'No One You Know'
} | ConvertTo-DDBItem
$keysAndAttributes = New-Object Amazon.DynamoDBv2.Model.KeysAndAttributes
$list = New-Object 'System.Collections.Generic.List[System.Collections.Generic.Dictionary[String, Amazon.DynamoDBv2.Model.AttributeValue]]'
$list.Add($key)
$keysAndAttributes.Keys = $list
$requestItem = @{
'Music' = [Amazon.DynamoDBv2.Model.KeysAndAttributes]$keysAndAttributes
'Songs' = [Amazon.DynamoDBv2.Model.KeysAndAttributes]$keysAndAttributes
}
$batchItems = Get-DDBBatchItem -RequestItem $requestItem
$batchItems.GetEnumerator() | ForEach-Object {$PSItem.Value} | ConvertFrom-DDBItem
```
**输出：**
```
Name Value
---- -----
Artist No One You Know
SongTitle Somewhere Down The Road
AlbumTitle Somewhat Famous
CriticRating 10
Genre Country
Price 1.94
Artist No One You Know
SongTitle Somewhere Down The Road
AlbumTitle Somewhat Famous
CriticRating 10
Genre Country
Price 1.94
```
+ 有关 API 详细信息，请参阅《AWS Tools for PowerShell Cmdlet Reference (V5)》**中的 [BatchGetItem](https://docs.aws.amazon.com/powershell/v5/reference)。
------
#### [ Python ]
**适用于 Python 的 SDK（Boto3）**
查看 GitHub，了解更多信息。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/python/example_code/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
```
import decimal
import json
import logging
import os
import pprint
import time
import boto3
from botocore.exceptions import ClientError
logger = logging.getLogger(__name__)
dynamodb = boto3.resource("dynamodb")
MAX_GET_SIZE = 100 # Amazon DynamoDB rejects a get batch larger than 100 items.
def do_batch_get(batch_keys):
"""
Gets a batch of items from Amazon DynamoDB. Batches can contain keys from
more than one table.
When Amazon DynamoDB cannot process all items in a batch, a set of unprocessed
keys is returned. This function uses an exponential backoff algorithm to retry
getting the unprocessed keys until all are retrieved or the specified
number of tries is reached.
:param batch_keys: The set of keys to retrieve. A batch can contain at most 100
keys. Otherwise, Amazon DynamoDB returns an error.
:return: The dictionary of retrieved items grouped under their respective
table names.
"""
tries = 0
max_tries = 5
sleepy_time = 1 # Start with 1 second of sleep, then exponentially increase.
retrieved = {key: [] for key in batch_keys}
while tries < max_tries:
response = dynamodb.batch_get_item(RequestItems=batch_keys)
# Collect any retrieved items and retry unprocessed keys.
for key in response.get("Responses", []):
retrieved[key] += response["Responses"][key]
unprocessed = response["UnprocessedKeys"]
if len(unprocessed) > 0:
batch_keys = unprocessed
unprocessed_count = sum(
[len(batch_key["Keys"]) for batch_key in batch_keys.values()]
)
logger.info(
"%s unprocessed keys returned. Sleep, then retry.", unprocessed_count
)
tries += 1
if tries < max_tries:
logger.info("Sleeping for %s seconds.", sleepy_time)
time.sleep(sleepy_time)
sleepy_time = min(sleepy_time * 2, 32)
else:
break
return retrieved
```
+ 有关 API 详细信息，请参阅《AWS SDK for Python (Boto3) API Reference》**中的 [BatchGetItem](https://docs.aws.amazon.com/goto/boto3/dynamodb-2012-08-10/BatchGetItem)。
------
#### [ Swift ]
**适用于 Swift 的 SDK**
查看 GitHub，了解更多信息。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/swift/example_code/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
```
import AWSDynamoDB
/// Gets an array of `Movie` objects describing all the movies in the
/// specified list. Any movies that aren't found in the list have no
/// corresponding entry in the resulting array.
///
/// - Parameters
/// - keys: An array of tuples, each of which specifies the title and
/// release year of a movie to fetch from the table.
///
/// - Returns:
/// - An array of `Movie` objects describing each match found in the
/// table.
///
/// - Throws:
/// - `MovieError.ClientUninitialized` if the DynamoDB client has not
/// been initialized.
/// - DynamoDB errors are thrown without change.
func batchGet(keys: [(title: String, year: Int)]) async throws -> [Movie] {
do {
guard let client = self.ddbClient else {
throw MovieError.ClientUninitialized
}
var movieList: [Movie] = []
var keyItems: [[Swift.String: DynamoDBClientTypes.AttributeValue]] = []
// Convert the list of keys into the form used by DynamoDB.
for key in keys {
let item: [Swift.String: DynamoDBClientTypes.AttributeValue] = [
"title": .s(key.title),
"year": .n(String(key.year))
]
keyItems.append(item)
}
// Create the input record for `batchGetItem()`. The list of requested
// items is in the `requestItems` property. This array contains one
// entry for each table from which items are to be fetched. In this
// example, there's only one table containing the movie data.
//
// If we wanted this program to also support searching for matches
// in a table of book data, we could add a second `requestItem`
// mapping the name of the book table to the list of items we want to
// find in it.
let input = BatchGetItemInput(
requestItems: [
self.tableName: .init(
consistentRead: true,
keys: keyItems
)
]
)
// Fetch the matching movies from the table.
let output = try await client.batchGetItem(input: input)
// Get the set of responses. If there aren't any, return the empty
// movie list.
guard let responses = output.responses else {
return movieList
}
// Get the list of matching items for the table with the name
// `tableName`.
guard let responseList = responses[self.tableName] else {
return movieList
}
// Create `Movie` items for each of the matching movies in the table
// and add them to the `MovieList` array.
for response in responseList {
try movieList.append(Movie(withItem: response))
}
return movieList
} catch {
print("ERROR: batchGet", dump(error))
throw error
}
}
```
+ 有关 API 详细信息，请参阅《AWS SDK for Swift API 参考》**中的 [BatchGetItem](https://sdk.amazonaws.com/swift/api/awsdynamodb/latest/documentation/awsdynamodb/dynamodbclient/batchgetitem(input:))。
------
有关 AWS SDK 开发人员指南和代码示例的完整列表，请参阅 [结合使用 DynamoDB 与 AWS SDK](sdk-general-information-section.md) 本主题还包括有关入门的信息以及有关先前的 SDK 版本的详细信息。
# 将 `BatchWriteItem` 与 AWS SDK 或 CLI 配合使用
以下代码示例演示如何使用 `BatchWriteItem`。
操作示例是大型程序的代码摘录，必须在上下文中运行。在以下代码示例中，您可以查看此操作的上下文：
+ [了解基本功能](example_dynamodb_Scenario_GettingStartedMovies_section.md)
------
#### [ .NET ]
**适用于 .NET 的 SDK (v4)**
查看 GitHub，了解更多信息。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/dotnetv4/DynamoDB#code-examples)中查找完整示例，了解如何进行设置和运行。
将一批项目写入影片表。
```
///
/// Loads the contents of a JSON file into a list of movies to be
/// added to the DynamoDB table.
///
/// The name of the JSON file.
/// A generic list of movie objects.
public List ImportMovies(string movieFileName)
{
var moviesList = new List();
if (!File.Exists(movieFileName))
{
return moviesList;
}
using var sr = new StreamReader(movieFileName);
string json = sr.ReadToEnd();
var allMovies = JsonSerializer.Deserialize>(
json,
new JsonSerializerOptions
{
PropertyNameCaseInsensitive = true
});
// Now return the first 250 entries.
if (allMovies != null && allMovies.Any())
{
moviesList = allMovies.GetRange(0, 250);
}
return moviesList;
}
///
/// Writes 250 items to the movie table.
///
/// A string containing the full path to
/// the JSON file containing movie data.
/// The name of the table to write items to.
/// A long integer value representing the number of movies
/// imported from the JSON file.
public async Task BatchWriteItemsAsync(
string movieFileName, string tableName)
{
try
{
var movies = ImportMovies(movieFileName);
if (!movies.Any())
{
Console.WriteLine("Couldn't find the JSON file with movie data.");
return 0;
}
var context = new DynamoDBContextBuilder()
// Optional call to provide a specific instance of IAmazonDynamoDB
.WithDynamoDBClient(() => _amazonDynamoDB)
.Build();
var movieBatch = context.CreateBatchWrite(
new BatchWriteConfig()
{
OverrideTableName = tableName
});
movieBatch.AddPutItems(movies);
Console.WriteLine("Adding imported movies to the table.");
await movieBatch.ExecuteAsync();
return movies.Count;
}
catch (ResourceNotFoundException ex)
{
Console.WriteLine($"Table was not found during batch write operation. {ex.Message}");
throw;
}
catch (AmazonDynamoDBException ex)
{
Console.WriteLine($"An Amazon DynamoDB error occurred during batch write operation. {ex.Message}");
throw;
}
catch (Exception ex)
{
Console.WriteLine($"An error occurred during batch write operation. {ex.Message}");
throw;
}
}
```
+ 有关 API 详细信息，请参阅《适用于 .NET 的 AWS SDK API Reference》**中的 [BatchWriteItem](https://docs.aws.amazon.com/goto/DotNetSDKV4/dynamodb-2012-08-10/BatchWriteItem)。
------
#### [ Bash ]
**AWS CLI 及 Bash 脚本**
查看 GitHub，了解更多信息。查找完整示例，了解如何在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/aws-cli/bash-linux/dynamodb#code-examples)中进行设置和运行。
```
##############################################################################
# function dynamodb_batch_write_item
#
# This function writes a batch of items into a DynamoDB table.
#
# Parameters:
# -i item -- Path to json file containing the items to write.
#
# Returns:
# 0 - If successful.
# 1 - If it fails.
############################################################################
function dynamodb_batch_write_item() {
local item response
local option OPTARG # Required to use getopts command in a function.
#######################################
# Function usage explanation
#######################################
function usage() {
echo "function dynamodb_batch_write_item"
echo "Write a batch of items into a DynamoDB table."
echo " -i item -- Path to json file containing the items to write."
echo ""
}
while getopts "i:h" option; do
case "${option}" in
i) item="${OPTARG}" ;;
h)
usage
return 0
;;
\?)
echo "Invalid parameter"
usage
return 1
;;
esac
done
export OPTIND=1
if [[ -z "$item" ]]; then
errecho "ERROR: You must provide an item with the -i parameter."
usage
return 1
fi
iecho "Parameters:\n"
iecho " table_name: $table_name"
iecho " item: $item"
iecho ""
response=$(aws dynamodb batch-write-item \
--request-items file://"$item")
local error_code=${?}
if [[ $error_code -ne 0 ]]; then
aws_cli_error_log $error_code
errecho "ERROR: AWS reports batch-write-item operation failed.$response"
return 1
fi
return 0
}
```
本示例中使用的实用程序函数。
```
###############################################################################
# function iecho
#
# This function enables the script to display the specified text only if
# the global variable $VERBOSE is set to true.
###############################################################################
function iecho() {
if [[ $VERBOSE == true ]]; then
echo "$@"
fi
}
###############################################################################
# function errecho
#
# This function outputs everything sent to it to STDERR (standard error output).
###############################################################################
function errecho() {
printf "%s\n" "$*" 1>&2
}
##############################################################################
# function aws_cli_error_log()
#
# This function is used to log the error messages from the AWS CLI.
#
# See https://docs.aws.amazon.com/cli/latest/topic/return-codes.html#cli-aws-help-return-codes.
#
# The function expects the following argument:
# $1 - The error code returned by the AWS CLI.
#
# Returns:
# 0: - Success.
#
##############################################################################
function aws_cli_error_log() {
local err_code=$1
errecho "Error code : $err_code"
if [ "$err_code" == 1 ]; then
errecho " One or more S3 transfers failed."
elif [ "$err_code" == 2 ]; then
errecho " Command line failed to parse."
elif [ "$err_code" == 130 ]; then
errecho " Process received SIGINT."
elif [ "$err_code" == 252 ]; then
errecho " Command syntax invalid."
elif [ "$err_code" == 253 ]; then
errecho " The system environment or configuration was invalid."
elif [ "$err_code" == 254 ]; then
errecho " The service returned an error."
elif [ "$err_code" == 255 ]; then
errecho " 255 is a catch-all error."
fi
return 0
}
```
+ 有关 API 详细信息，请参阅《AWS CLI 命令参考》**中的 [BatchWriteItem](https://docs.aws.amazon.com/goto/aws-cli/dynamodb-2012-08-10/BatchWriteItem)。
------
#### [ C\$1\$1 ]
**SDK for C\$1\$1**
查看 GitHub，了解更多信息。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/cpp/example_code/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
```
//! Batch write items from a JSON file.
/*!
\sa batchWriteItem()
\param jsonFilePath: JSON file path.
\param clientConfiguration: AWS client configuration.
\return bool: Function succeeded.
*/
/*
* The input for this routine is a JSON file that you can download from the following URL:
* https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/SampleData.html.
*
* The JSON data uses the BatchWriteItem API request syntax. The JSON strings are
* converted to AttributeValue objects. These AttributeValue objects will then generate
* JSON strings when constructing the BatchWriteItem request, essentially outputting
* their input.
*
* This is perhaps an artificial example, but it demonstrates the APIs.
*/
bool AwsDoc::DynamoDB::batchWriteItem(const Aws::String &jsonFilePath,
const Aws::Client::ClientConfiguration &clientConfiguration) {
std::ifstream fileStream(jsonFilePath);
if (!fileStream) {
std::cerr << "Error: could not open file '" << jsonFilePath << "'."
<< std::endl;
}
std::stringstream stringStream;
stringStream << fileStream.rdbuf();
Aws::Utils::Json::JsonValue jsonValue(stringStream);
Aws::DynamoDB::Model::BatchWriteItemRequest batchWriteItemRequest;
Aws::Map level1Map = jsonValue.View().GetAllObjects();
for (const auto &level1Entry: level1Map) {
const Aws::Utils::Json::JsonView &entriesView = level1Entry.second;
const Aws::String &tableName = level1Entry.first;
// The JSON entries at this level are as follows:
// key - table name
// value - list of request objects
if (!entriesView.IsListType()) {
std::cerr << "Error: JSON file entry '"
<< tableName << "' is not a list." << std::endl;
continue;
}
Aws::Utils::Array entries = entriesView.AsArray();
Aws::Vector writeRequests;
if (AwsDoc::DynamoDB::addWriteRequests(tableName, entries,
writeRequests)) {
batchWriteItemRequest.AddRequestItems(tableName, writeRequests);
}
}
Aws::DynamoDB::DynamoDBClient dynamoClient(clientConfiguration);
Aws::DynamoDB::Model::BatchWriteItemOutcome outcome = dynamoClient.BatchWriteItem(
batchWriteItemRequest);
if (outcome.IsSuccess()) {
std::cout << "DynamoDB::BatchWriteItem was successful." << std::endl;
}
else {
std::cerr << "Error with DynamoDB::BatchWriteItem. "
<< outcome.GetError().GetMessage()
<< std::endl;
return false;
}
return outcome.IsSuccess();
}
//! Convert requests in JSON format to a vector of WriteRequest objects.
/*!
\sa addWriteRequests()
\param tableName: Name of the table for the write operations.
\param requestsJson: Request data in JSON format.
\param writeRequests: Vector to receive the WriteRequest objects.
\return bool: Function succeeded.
*/
bool AwsDoc::DynamoDB::addWriteRequests(const Aws::String &tableName,
const Aws::Utils::Array &requestsJson,
Aws::Vector &writeRequests) {
for (size_t i = 0; i < requestsJson.GetLength(); ++i) {
const Aws::Utils::Json::JsonView &requestsEntry = requestsJson[i];
if (!requestsEntry.IsObject()) {
std::cerr << "Error: incorrect requestsEntry type "
<< requestsEntry.WriteReadable() << std::endl;
return false;
}
Aws::Map requestsMap = requestsEntry.GetAllObjects();
for (const auto &request: requestsMap) {
const Aws::String &requestType = request.first;
const Aws::Utils::Json::JsonView &requestJsonView = request.second;
if (requestType == "PutRequest") {
if (!requestJsonView.ValueExists("Item")) {
std::cerr << "Error: item key missing for requests "
<< requestJsonView.WriteReadable() << std::endl;
return false;
}
Aws::Map attributes;
if (!getAttributeObjectsMap(requestJsonView.GetObject("Item"),
attributes)) {
std::cerr << "Error getting attributes "
<< requestJsonView.WriteReadable() << std::endl;
return false;
}
Aws::DynamoDB::Model::PutRequest putRequest;
putRequest.SetItem(attributes);
writeRequests.push_back(
Aws::DynamoDB::Model::WriteRequest().WithPutRequest(
putRequest));
}
else {
std::cerr << "Error: unimplemented request type '" << requestType
<< "'." << std::endl;
}
}
}
return true;
}
//! Generate a map of AttributeValue objects from JSON records.
/*!
\sa getAttributeObjectsMap()
\param jsonView: JSONView of attribute records.
\param writeRequests: Map to receive the AttributeValue objects.
\return bool: Function succeeded.
*/
bool
AwsDoc::DynamoDB::getAttributeObjectsMap(const Aws::Utils::Json::JsonView &jsonView,
Aws::Map &attributes) {
Aws::Map objectsMap = jsonView.GetAllObjects();
for (const auto &entry: objectsMap) {
const Aws::String &attributeKey = entry.first;
const Aws::Utils::Json::JsonView &attributeJsonView = entry.second;
if (!attributeJsonView.IsObject()) {
std::cerr << "Error: attribute not an object "
<< attributeJsonView.WriteReadable() << std::endl;
return false;
}
attributes.emplace(attributeKey,
Aws::DynamoDB::Model::AttributeValue(attributeJsonView));
}
return true;
}
```
+ 有关 API 详细信息，请参阅 *适用于 C\$1\$1 的 AWS SDK API 参考*中的 [BatchWriteItem](https://docs.aws.amazon.com/goto/SdkForCpp/dynamodb-2012-08-10/BatchWriteItem)。
------
#### [ CLI ]
**AWS CLI**
**向表中添加多个项**
以下 `batch-write-item` 示例使用一批三个 `PutItem` 请求向 `MusicCollection` 表中添加三个新项。它还会请求有关操作所用的写入容量单位数以及操作修改的任何项集合的信息。
```
aws dynamodb batch-write-item \
--request-items file://request-items.json \
--return-consumed-capacity INDEXES \
--return-item-collection-metrics SIZE
```
的内容`request-items.json`：
```
{
"MusicCollection": [
{
"PutRequest": {
"Item": {
"Artist": {"S": "No One You Know"},
"SongTitle": {"S": "Call Me Today"},
"AlbumTitle": {"S": "Somewhat Famous"}
}
}
},
{
"PutRequest": {
"Item": {
"Artist": {"S": "Acme Band"},
"SongTitle": {"S": "Happy Day"},
"AlbumTitle": {"S": "Songs About Life"}
}
}
},
{
"PutRequest": {
"Item": {
"Artist": {"S": "No One You Know"},
"SongTitle": {"S": "Scared of My Shadow"},
"AlbumTitle": {"S": "Blue Sky Blues"}
}
}
}
]
}
```
输出：
```
{
"UnprocessedItems": {},
"ItemCollectionMetrics": {
"MusicCollection": [
{
"ItemCollectionKey": {
"Artist": {
"S": "No One You Know"
}
},
"SizeEstimateRangeGB": [
0.0,
1.0
]
},
{
"ItemCollectionKey": {
"Artist": {
"S": "Acme Band"
}
},
"SizeEstimateRangeGB": [
0.0,
1.0
]
}
]
},
"ConsumedCapacity": [
{
"TableName": "MusicCollection",
"CapacityUnits": 6.0,
"Table": {
"CapacityUnits": 3.0
},
"LocalSecondaryIndexes": {
"AlbumTitleIndex": {
"CapacityUnits": 3.0
}
}
}
]
}
```
有关更多信息，请参阅《Amazon DynamoDB 开发人员指南》**中的[基本操作](https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/WorkingWithItems.html#WorkingWithItems.BatchOperations)。
+ 有关 API 详细信息，请参阅《AWS CLI 命令参考》**中的 [BatchWriteItem](https://awscli.amazonaws.com/v2/documentation/api/latest/reference/dynamodb/batch-write-item.html)。
------
#### [ Go ]
**适用于 Go 的 SDK V2**
查看 GitHub，了解更多信息。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/gov2/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
```
import (
"context"
"errors"
"log"
"time"
"github.com/aws/aws-sdk-go-v2/aws"
"github.com/aws/aws-sdk-go-v2/feature/dynamodb/attributevalue"
"github.com/aws/aws-sdk-go-v2/feature/dynamodb/expression"
"github.com/aws/aws-sdk-go-v2/service/dynamodb"
"github.com/aws/aws-sdk-go-v2/service/dynamodb/types"
)
// TableBasics encapsulates the Amazon DynamoDB service actions used in the examples.
// It contains a DynamoDB service client that is used to act on the specified table.
type TableBasics struct {
DynamoDbClient *dynamodb.Client
TableName string
}
// AddMovieBatch adds a slice of movies to the DynamoDB table. The function sends
// batches of 25 movies to DynamoDB until all movies are added or it reaches the
// specified maximum.
func (basics TableBasics) AddMovieBatch(ctx context.Context, movies []Movie, maxMovies int) (int, error) {
var err error
var item map[string]types.AttributeValue
written := 0
batchSize := 25 // DynamoDB allows a maximum batch size of 25 items.
start := 0
end := start + batchSize
for start < maxMovies && start < len(movies) {
var writeReqs []types.WriteRequest
if end > len(movies) {
end = len(movies)
}
for _, movie := range movies[start:end] {
item, err = attributevalue.MarshalMap(movie)
if err != nil {
log.Printf("Couldn't marshal movie %v for batch writing. Here's why: %v\n", movie.Title, err)
} else {
writeReqs = append(
writeReqs,
types.WriteRequest{PutRequest: &types.PutRequest{Item: item}},
)
}
}
_, err = basics.DynamoDbClient.BatchWriteItem(ctx, &dynamodb.BatchWriteItemInput{
RequestItems: map[string][]types.WriteRequest{basics.TableName: writeReqs}})
if err != nil {
log.Printf("Couldn't add a batch of movies to %v. Here's why: %v\n", basics.TableName, err)
} else {
written += len(writeReqs)
}
start = end
end += batchSize
}
return written, err
}
```
定义本示例中使用的 Movie 结构。
```
import (
"archive/zip"
"bytes"
"encoding/json"
"fmt"
"io"
"log"
"net/http"
"github.com/aws/aws-sdk-go-v2/feature/dynamodb/attributevalue"
"github.com/aws/aws-sdk-go-v2/service/dynamodb/types"
)
// Movie encapsulates data about a movie. Title and Year are the composite primary key
// of the movie in Amazon DynamoDB. Title is the sort key, Year is the partition key,
// and Info is additional data.
type Movie struct {
Title string `dynamodbav:"title"`
Year int `dynamodbav:"year"`
Info map[string]interface{} `dynamodbav:"info"`
}
// GetKey returns the composite primary key of the movie in a format that can be
// sent to DynamoDB.
func (movie Movie) GetKey() map[string]types.AttributeValue {
title, err := attributevalue.Marshal(movie.Title)
if err != nil {
panic(err)
}
year, err := attributevalue.Marshal(movie.Year)
if err != nil {
panic(err)
}
return map[string]types.AttributeValue{"title": title, "year": year}
}
// String returns the title, year, rating, and plot of a movie, formatted for the example.
func (movie Movie) String() string {
return fmt.Sprintf("%v\n\tReleased: %v\n\tRating: %v\n\tPlot: %v\n",
movie.Title, movie.Year, movie.Info["rating"], movie.Info["plot"])
}
```
+ 有关 API 详细信息，请参阅《适用于 Go 的 AWS SDK API Reference》**中的 [BatchWriteItem](https://pkg.go.dev/github.com/aws/aws-sdk-go-v2/service/dynamodb#Client.BatchWriteItem)。
------
#### [ Java ]
**适用于 Java 的 SDK 2.x**
查看 GitHub，了解更多信息。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javav2/example_code/dynamodb/#code-examples)中查找完整示例，了解如何进行设置和运行。
使用服务客户端将许多项目插入到表中。
```
import software.amazon.awssdk.regions.Region;
import software.amazon.awssdk.services.dynamodb.DynamoDbClient;
import software.amazon.awssdk.services.dynamodb.model.AttributeValue;
import software.amazon.awssdk.services.dynamodb.model.BatchWriteItemRequest;
import software.amazon.awssdk.services.dynamodb.model.BatchWriteItemResponse;
import software.amazon.awssdk.services.dynamodb.model.DynamoDbException;
import software.amazon.awssdk.services.dynamodb.model.PutRequest;
import software.amazon.awssdk.services.dynamodb.model.WriteRequest;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
/**
* Before running this Java V2 code example, set up your development environment, including your credentials.
*
* For more information, see the following documentation topic:
*
* https://docs.aws.amazon.com/sdk-for-java/latest/developer-guide/get-started.html
*/
public class BatchWriteItems {
public static void main(String[] args){
final String usage = """
Usage:
Where:
tableName - The Amazon DynamoDB table (for example, Music).\s
""";
String tableName = "Music";
Region region = Region.US_EAST_1;
DynamoDbClient dynamoDbClient = DynamoDbClient.builder()
.region(region)
.build();
addBatchItems(dynamoDbClient, tableName);
}
public static void addBatchItems(DynamoDbClient dynamoDbClient, String tableName) {
// Specify the updates you want to perform.
List writeRequests = new ArrayList<>();
// Set item 1.
Map item1Attributes = new HashMap<>();
item1Attributes.put("Artist", AttributeValue.builder().s("Artist1").build());
item1Attributes.put("Rating", AttributeValue.builder().s("5").build());
item1Attributes.put("Comments", AttributeValue.builder().s("Great song!").build());
item1Attributes.put("SongTitle", AttributeValue.builder().s("SongTitle1").build());
writeRequests.add(WriteRequest.builder().putRequest(PutRequest.builder().item(item1Attributes).build()).build());
// Set item 2.
Map item2Attributes = new HashMap<>();
item2Attributes.put("Artist", AttributeValue.builder().s("Artist2").build());
item2Attributes.put("Rating", AttributeValue.builder().s("4").build());
item2Attributes.put("Comments", AttributeValue.builder().s("Nice melody.").build());
item2Attributes.put("SongTitle", AttributeValue.builder().s("SongTitle2").build());
writeRequests.add(WriteRequest.builder().putRequest(PutRequest.builder().item(item2Attributes).build()).build());
try {
// Create the BatchWriteItemRequest.
BatchWriteItemRequest batchWriteItemRequest = BatchWriteItemRequest.builder()
.requestItems(Map.of(tableName, writeRequests))
.build();
// Execute the BatchWriteItem operation.
BatchWriteItemResponse batchWriteItemResponse = dynamoDbClient.batchWriteItem(batchWriteItemRequest);
// Process the response.
System.out.println("Batch write successful: " + batchWriteItemResponse);
} catch (DynamoDbException e) {
System.err.println(e.getMessage());
System.exit(1);
}
}
}
```
使用增强型客户端将许多项目插入到表中。
```
import com.example.dynamodb.Customer;
import com.example.dynamodb.Music;
import software.amazon.awssdk.enhanced.dynamodb.DynamoDbEnhancedClient;
import software.amazon.awssdk.enhanced.dynamodb.DynamoDbTable;
import software.amazon.awssdk.enhanced.dynamodb.Key;
import software.amazon.awssdk.enhanced.dynamodb.TableSchema;
import software.amazon.awssdk.enhanced.dynamodb.model.BatchWriteItemEnhancedRequest;
import software.amazon.awssdk.enhanced.dynamodb.model.WriteBatch;
import software.amazon.awssdk.regions.Region;
import software.amazon.awssdk.services.dynamodb.DynamoDbClient;
import software.amazon.awssdk.services.dynamodb.model.DynamoDbException;
import java.time.Instant;
import java.time.LocalDate;
import java.time.LocalDateTime;
import java.time.ZoneOffset;
/*
* Before running this code example, create an Amazon DynamoDB table named Customer with these columns:
* - id - the id of the record that is the key
* - custName - the customer name
* - email - the email value
* - registrationDate - an instant value when the item was added to the table
*
* Also, ensure that you have set up your development environment, including your credentials.
*
* For information, see this documentation topic:
*
* https://docs.aws.amazon.com/sdk-for-java/latest/developer-guide/get-started.html
*/
public class EnhancedBatchWriteItems {
public static void main(String[] args) {
Region region = Region.US_EAST_1;
DynamoDbClient ddb = DynamoDbClient.builder()
.region(region)
.build();
DynamoDbEnhancedClient enhancedClient = DynamoDbEnhancedClient.builder()
.dynamoDbClient(ddb)
.build();
putBatchRecords(enhancedClient);
ddb.close();
}
public static void putBatchRecords(DynamoDbEnhancedClient enhancedClient) {
try {
DynamoDbTable customerMappedTable = enhancedClient.table("Customer",
TableSchema.fromBean(Customer.class));
DynamoDbTable musicMappedTable = enhancedClient.table("Music",
TableSchema.fromBean(Music.class));
LocalDate localDate = LocalDate.parse("2020-04-07");
LocalDateTime localDateTime = localDate.atStartOfDay();
Instant instant = localDateTime.toInstant(ZoneOffset.UTC);
Customer record2 = new Customer();
record2.setCustName("Fred Pink");
record2.setId("id110");
record2.setEmail("fredp@noserver.com");
record2.setRegistrationDate(instant);
Customer record3 = new Customer();
record3.setCustName("Susan Pink");
record3.setId("id120");
record3.setEmail("spink@noserver.com");
record3.setRegistrationDate(instant);
Customer record4 = new Customer();
record4.setCustName("Jerry orange");
record4.setId("id101");
record4.setEmail("jorange@noserver.com");
record4.setRegistrationDate(instant);
BatchWriteItemEnhancedRequest batchWriteItemEnhancedRequest = BatchWriteItemEnhancedRequest
.builder()
.writeBatches(
WriteBatch.builder(Customer.class) // add items to the Customer
// table
.mappedTableResource(customerMappedTable)
.addPutItem(builder -> builder.item(record2))
.addPutItem(builder -> builder.item(record3))
.addPutItem(builder -> builder.item(record4))
.build(),
WriteBatch.builder(Music.class) // delete an item from the Music
// table
.mappedTableResource(musicMappedTable)
.addDeleteItem(builder -> builder.key(
Key.builder().partitionValue(
"Famous Band")
.build()))
.build())
.build();
// Add three items to the Customer table and delete one item from the Music
// table.
enhancedClient.batchWriteItem(batchWriteItemEnhancedRequest);
System.out.println("done");
} catch (DynamoDbException e) {
System.err.println(e.getMessage());
System.exit(1);
}
}
}
```
+ 有关 API 详细信息，请参阅《AWS SDK for Java 2.x API Reference》**中的 [BatchWriteItem](https://docs.aws.amazon.com/goto/SdkForJavaV2/dynamodb-2012-08-10/BatchWriteItem)。
------
#### [ JavaScript ]
**SDK for JavaScript (v3)**
查看 GitHub，了解更多信息。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javascriptv3/example_code/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
此示例使用文档客户端来简化在 DynamoDB 中处理项目的过程。有关 API 详细信息，请参阅 [BatchWrite](https://docs.aws.amazon.com/AWSJavaScriptSDK/v3/latest/Package/-aws-sdk-lib-dynamodb/Class/BatchWriteCommand/)。
```
import { DynamoDBClient } from "@aws-sdk/client-dynamodb";
import {
BatchWriteCommand,
DynamoDBDocumentClient,
} from "@aws-sdk/lib-dynamodb";
import { readFileSync } from "node:fs";
// These modules are local to our GitHub repository. We recommend cloning
// the project from GitHub if you want to run this example.
// For more information, see https://github.com/awsdocs/aws-doc-sdk-examples.
import { dirnameFromMetaUrl } from "@aws-doc-sdk-examples/lib/utils/util-fs.js";
import { chunkArray } from "@aws-doc-sdk-examples/lib/utils/util-array.js";
const dirname = dirnameFromMetaUrl(import.meta.url);
const client = new DynamoDBClient({});
const docClient = DynamoDBDocumentClient.from(client);
export const main = async () => {
const file = readFileSync(
`${dirname}../../../../../resources/sample_files/movies.json`,
);
const movies = JSON.parse(file.toString());
// chunkArray is a local convenience function. It takes an array and returns
// a generator function. The generator function yields every N items.
const movieChunks = chunkArray(movies, 25);
// For every chunk of 25 movies, make one BatchWrite request.
for (const chunk of movieChunks) {
const putRequests = chunk.map((movie) => ({
PutRequest: {
Item: movie,
},
}));
const command = new BatchWriteCommand({
RequestItems: {
// An existing table is required. A composite key of 'title' and 'year' is recommended
// to account for duplicate titles.
BatchWriteMoviesTable: putRequests,
},
});
await docClient.send(command);
}
};
```
+ 有关 API 详细信息，请参阅《适用于 JavaScript 的 AWS SDK API Reference》**中的 [BatchWriteItem](https://docs.aws.amazon.com/AWSJavaScriptSDK/v3/latest/client/dynamodb/command/BatchWriteItemCommand)。
**SDK for JavaScript (v2)**
查看 GitHub，了解更多信息。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javascript/example_code/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
```
// Load the AWS SDK for Node.js
var AWS = require("aws-sdk");
// Set the region
AWS.config.update({ region: "REGION" });
// Create DynamoDB service object
var ddb = new AWS.DynamoDB({ apiVersion: "2012-08-10" });
var params = {
RequestItems: {
TABLE_NAME: [
{
PutRequest: {
Item: {
KEY: { N: "KEY_VALUE" },
ATTRIBUTE_1: { S: "ATTRIBUTE_1_VALUE" },
ATTRIBUTE_2: { N: "ATTRIBUTE_2_VALUE" },
},
},
},
{
PutRequest: {
Item: {
KEY: { N: "KEY_VALUE" },
ATTRIBUTE_1: { S: "ATTRIBUTE_1_VALUE" },
ATTRIBUTE_2: { N: "ATTRIBUTE_2_VALUE" },
},
},
},
],
},
};
ddb.batchWriteItem(params, function (err, data) {
if (err) {
console.log("Error", err);
} else {
console.log("Success", data);
}
});
```
+ 有关更多信息，请参阅《适用于 JavaScript 的 AWS SDK 开发人员指南》[https://docs.aws.amazon.com/sdk-for-javascript/v2/developer-guide/dynamodb-example-table-read-write-batch.html#dynamodb-example-table-read-write-batch-writing](https://docs.aws.amazon.com/sdk-for-javascript/v2/developer-guide/dynamodb-example-table-read-write-batch.html#dynamodb-example-table-read-write-batch-writing)。
+ 有关 API 详细信息，请参阅《适用于 JavaScript 的 AWS SDK API Reference》**中的 [BatchWriteItem](https://docs.aws.amazon.com/goto/AWSJavaScriptSDK/dynamodb-2012-08-10/BatchWriteItem)。
------
#### [ PHP ]
**适用于 PHP 的 SDK**
查看 GitHub，了解更多信息。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/php/example_code/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
```
public function writeBatch(string $TableName, array $Batch, int $depth = 2)
{
if (--$depth <= 0) {
throw new Exception("Max depth exceeded. Please try with fewer batch items or increase depth.");
}
$marshal = new Marshaler();
$total = 0;
foreach (array_chunk($Batch, 25) as $Items) {
foreach ($Items as $Item) {
$BatchWrite['RequestItems'][$TableName][] = ['PutRequest' => ['Item' => $marshal->marshalItem($Item)]];
}
try {
echo "Batching another " . count($Items) . " for a total of " . ($total += count($Items)) . " items!\n";
$response = $this->dynamoDbClient->batchWriteItem($BatchWrite);
$BatchWrite = [];
} catch (Exception $e) {
echo "uh oh...";
echo $e->getMessage();
die();
}
if ($total >= 250) {
echo "250 movies is probably enough. Right? We can stop there.\n";
break;
}
}
}
```
+ 有关 API 详细信息，请参阅 *适用于 PHP 的 AWS SDK API 参考*中的 [BatchWriteItem](https://docs.aws.amazon.com/goto/SdkForPHPV3/dynamodb-2012-08-10/BatchWriteItem)。
------
#### [ PowerShell ]
**适用于 PowerShell V4 的工具**
**示例 1：创建一个新项目，或将现有项目替换为 DynamoDB 表 Music 和 Songs 中的新项目。**
```
$item = @{
SongTitle = 'Somewhere Down The Road'
Artist = 'No One You Know'
AlbumTitle = 'Somewhat Famous'
Price = 1.94
Genre = 'Country'
CriticRating = 10.0
} | ConvertTo-DDBItem
$writeRequest = New-Object Amazon.DynamoDBv2.Model.WriteRequest
$writeRequest.PutRequest = [Amazon.DynamoDBv2.Model.PutRequest]$item
$requestItem = @{
'Music' = [Amazon.DynamoDBv2.Model.WriteRequest]($writeRequest)
'Songs' = [Amazon.DynamoDBv2.Model.WriteRequest]($writeRequest)
}
Set-DDBBatchItem -RequestItem $requestItem
```
+ 有关 API 详细信息，请参阅《AWS Tools for PowerShell Cmdlet Reference (V4)》**中的 [BatchWriteItem](https://docs.aws.amazon.com/powershell/v4/reference)。
**适用于 PowerShell V5 的工具**
**示例 1：创建一个新项目，或将现有项目替换为 DynamoDB 表 Music 和 Songs 中的新项目。**
```
$item = @{
SongTitle = 'Somewhere Down The Road'
Artist = 'No One You Know'
AlbumTitle = 'Somewhat Famous'
Price = 1.94
Genre = 'Country'
CriticRating = 10.0
} | ConvertTo-DDBItem
$writeRequest = New-Object Amazon.DynamoDBv2.Model.WriteRequest
$writeRequest.PutRequest = [Amazon.DynamoDBv2.Model.PutRequest]$item
$requestItem = @{
'Music' = [Amazon.DynamoDBv2.Model.WriteRequest]($writeRequest)
'Songs' = [Amazon.DynamoDBv2.Model.WriteRequest]($writeRequest)
}
Set-DDBBatchItem -RequestItem $requestItem
```
+ 有关 API 详细信息，请参阅《AWS Tools for PowerShell Cmdlet Reference (V5)》**中的 [BatchWriteItem](https://docs.aws.amazon.com/powershell/v5/reference)。
------
#### [ Python ]
**适用于 Python 的 SDK（Boto3）**
查看 GitHub，了解更多信息。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/python/example_code/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
```
class Movies:
"""Encapsulates an Amazon DynamoDB table of movie data.
Example data structure for a movie record in this table:
{
"year": 1999,
"title": "For Love of the Game",
"info": {
"directors": ["Sam Raimi"],
"release_date": "1999-09-15T00:00:00Z",
"rating": 6.3,
"plot": "A washed up pitcher flashes through his career.",
"rank": 4987,
"running_time_secs": 8220,
"actors": [
"Kevin Costner",
"Kelly Preston",
"John C. Reilly"
]
}
}
"""
def __init__(self, dyn_resource):
"""
:param dyn_resource: A Boto3 DynamoDB resource.
"""
self.dyn_resource = dyn_resource
# The table variable is set during the scenario in the call to
# 'exists' if the table exists. Otherwise, it is set by 'create_table'.
self.table = None
def write_batch(self, movies):
"""
Fills an Amazon DynamoDB table with the specified data, using the Boto3
Table.batch_writer() function to put the items in the table.
Inside the context manager, Table.batch_writer builds a list of
requests. On exiting the context manager, Table.batch_writer starts sending
batches of write requests to Amazon DynamoDB and automatically
handles chunking, buffering, and retrying.
:param movies: The data to put in the table. Each item must contain at least
the keys required by the schema that was specified when the
table was created.
"""
try:
with self.table.batch_writer() as writer:
for movie in movies:
writer.put_item(Item=movie)
except ClientError as err:
logger.error(
"Couldn't load data into table %s. Here's why: %s: %s",
self.table.name,
err.response["Error"]["Code"],
err.response["Error"]["Message"],
)
raise
```
+ 有关 API 详细信息，请参阅《AWS SDK for Python (Boto3) API Reference》**中的 [BatchWriteItem](https://docs.aws.amazon.com/goto/boto3/dynamodb-2012-08-10/BatchWriteItem)。
------
#### [ Ruby ]
**适用于 Ruby 的 SDK**
查看 GitHub，了解更多信息。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/ruby/example_code/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
```
class DynamoDBBasics
attr_reader :dynamo_resource, :table
def initialize(table_name)
client = Aws::DynamoDB::Client.new(region: 'us-east-1')
@dynamo_resource = Aws::DynamoDB::Resource.new(client: client)
@table = @dynamo_resource.table(table_name)
end
# Fills an Amazon DynamoDB table with the specified data. Items are sent in
# batches of 25 until all items are written.
#
# @param movies [Enumerable] The data to put in the table. Each item must contain at least
# the keys required by the schema that was specified when the
# table was created.
def write_batch(movies)
index = 0
slice_size = 25
while index < movies.length
movie_items = []
movies[index, slice_size].each do |movie|
movie_items.append({ put_request: { item: movie } })
end
@dynamo_resource.client.batch_write_item({ request_items: { @table.name => movie_items } })
index += slice_size
end
rescue Aws::DynamoDB::Errors::ServiceError => e
puts(
"Couldn't load data into table #{@table.name}. Here's why:"
)
puts("\t#{e.code}: #{e.message}")
raise
end
```
+ 有关 API 详细信息，请参阅 *适用于 Ruby 的 AWS SDK API 参考*中的 [BatchWriteItem](https://docs.aws.amazon.com/goto/SdkForRubyV3/dynamodb-2012-08-10/BatchWriteItem)。
------
#### [ Swift ]
**适用于 Swift 的 SDK**
查看 GitHub，了解更多信息。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/swift/example_code/dynamodb/#code-examples)中查找完整示例，了解如何进行设置和运行。
```
import AWSDynamoDB
/// Populate the movie database from the specified JSON file.
///
/// - Parameter jsonPath: Path to a JSON file containing movie data.
///
func populate(jsonPath: String) async throws {
do {
guard let client = self.ddbClient else {
throw MoviesError.UninitializedClient
}
// Create a Swift `URL` and use it to load the file into a `Data`
// object. Then decode the JSON into an array of `Movie` objects.
let fileUrl = URL(fileURLWithPath: jsonPath)
let jsonData = try Data(contentsOf: fileUrl)
var movieList = try JSONDecoder().decode([Movie].self, from: jsonData)
// Truncate the list to the first 200 entries or so for this example.
if movieList.count > 200 {
movieList = Array(movieList[...199])
}
// Before sending records to the database, break the movie list into
// 25-entry chunks, which is the maximum size of a batch item request.
let count = movieList.count
let chunks = stride(from: 0, to: count, by: 25).map {
Array(movieList[$0 ..< Swift.min($0 + 25, count)])
}
// For each chunk, create a list of write request records and populate
// them with `PutRequest` requests, each specifying one movie from the
// chunk. Once the chunk's items are all in the `PutRequest` list,
// send them to Amazon DynamoDB using the
// `DynamoDBClient.batchWriteItem()` function.
for chunk in chunks {
var requestList: [DynamoDBClientTypes.WriteRequest] = []
for movie in chunk {
let item = try await movie.getAsItem()
let request = DynamoDBClientTypes.WriteRequest(
putRequest: .init(
item: item
)
)
requestList.append(request)
}
let input = BatchWriteItemInput(requestItems: [tableName: requestList])
_ = try await client.batchWriteItem(input: input)
}
} catch {
print("ERROR: populate:", dump(error))
throw error
}
}
```
+ 有关 API 详细信息，请参阅《AWS SDK for Swift API 参考》**中的 [BatchWriteItem](https://sdk.amazonaws.com/swift/api/awsdynamodb/latest/documentation/awsdynamodb/dynamodbclient/batchwriteitem(input:))。
------
有关 AWS SDK 开发人员指南和代码示例的完整列表，请参阅 [结合使用 DynamoDB 与 AWS SDK](sdk-general-information-section.md) 本主题还包括有关入门的信息以及有关先前的 SDK 版本的详细信息。
# 将 `CreateTable` 与 AWS SDK 或 CLI 配合使用
以下代码示例演示如何使用 `CreateTable`。
操作示例是大型程序的代码摘录，必须在上下文中运行。您可以在以下代码示例中查看此操作的上下文：
+ [了解基本功能](example_dynamodb_Scenario_GettingStartedMovies_section.md)
+ [借助 DAX 加快读取速度](example_dynamodb_Usage_DaxDemo_section.md)
+ [高级全局二级索引方案](example_dynamodb_Scenario_GSIAdvanced_section.md)
+ [创建带有全局二级索引的表](example_dynamodb_CreateTableWithGlobalSecondaryIndex_section.md)
+ [创建启用了热吞吐量的表](example_dynamodb_CreateTableWarmThroughput_section.md)
+ [创建和管理用于演示 MREC 的全局表](example_dynamodb_Scenario_GlobalTableOperations_section.md)
+ [创建和管理 MRSC 全局表](example_dynamodb_Scenario_MRSCGlobalTables_section.md)
+ [管理全局二级索引](example_dynamodb_Scenario_GSILifecycle_section.md)
+ [管理基于资源的策略](example_dynamodb_Scenario_ResourcePolicyLifecycle_section.md)
+ [设置基于属性的访问控制](example_dynamodb_Scenario_ABACSetup_section.md)
+ [使用全局表和多区域复制最终一致性（MREC）](example_dynamodb_Scenario_MultiRegionReplication_section.md)
+ [处理本地二级索引](example_dynamodb_Scenario_LSIExamples_section.md)
+ [使用资源标记](example_dynamodb_Scenario_TaggingExamples_section.md)
+ [处理 Streams 和生存时间](example_dynamodb_Scenario_StreamsAndTTL_section.md)
+ [处理表加密](example_dynamodb_Scenario_EncryptionExamples_section.md)
------
#### [ .NET ]
**适用于 .NET 的 SDK (v4)**
查看 GitHub，了解更多信息。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/dotnetv4/DynamoDB#code-examples)中查找完整示例，了解如何进行设置和运行。
```
///
/// Creates a new Amazon DynamoDB table and then waits for the new
/// table to become active.
///
/// The name of the table to create.
/// A Boolean value indicating the success of the operation.
public async Task CreateMovieTableAsync(string tableName)
{
try
{
var response = await _amazonDynamoDB.CreateTableAsync(new CreateTableRequest
{
TableName = tableName,
AttributeDefinitions = new List()
{
new AttributeDefinition
{
AttributeName = "title",
AttributeType = ScalarAttributeType.S,
},
new AttributeDefinition
{
AttributeName = "year",
AttributeType = ScalarAttributeType.N,
},
},
KeySchema = new List()
{
new KeySchemaElement
{
AttributeName = "year",
KeyType = KeyType.HASH,
},
new KeySchemaElement
{
AttributeName = "title",
KeyType = KeyType.RANGE,
},
},
BillingMode = BillingMode.PAY_PER_REQUEST,
});
// Wait until the table is ACTIVE and then report success.
Console.Write("Waiting for table to become active...");
var request = new DescribeTableRequest
{
TableName = response.TableDescription.TableName,
};
TableStatus status;
int sleepDuration = 2000;
do
{
Thread.Sleep(sleepDuration);
var describeTableResponse = await _amazonDynamoDB.DescribeTableAsync(request);
status = describeTableResponse.Table.TableStatus;
Console.Write(".");
}
while (status != "ACTIVE");
return status == TableStatus.ACTIVE;
}
catch (ResourceInUseException ex)
{
Console.WriteLine($"Table {tableName} already exists. {ex.Message}");
throw;
}
catch (AmazonDynamoDBException ex)
{
Console.WriteLine($"An Amazon DynamoDB error occurred while creating table {tableName}. {ex.Message}");
throw;
}
catch (Exception ex)
{
Console.WriteLine($"An error occurred while creating table {tableName}. {ex.Message}");
throw;
}
}
```
+ 有关 API 详细信息，请参阅《适用于 .NET 的 AWS SDK API Reference》**中的 [CreateTable](https://docs.aws.amazon.com/goto/DotNetSDKV4/dynamodb-2012-08-10/CreateTable)。
------
#### [ Bash ]
**AWS CLI 及 Bash 脚本**
查看 GitHub，了解更多信息。查找完整示例，了解如何在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/aws-cli/bash-linux/dynamodb#code-examples)中进行设置和运行。
```
###############################################################################
# function dynamodb_create_table
#
# This function creates an Amazon DynamoDB table.
#
# Parameters:
# -n table_name -- The name of the table to create.
# -a attribute_definitions -- JSON file path of a list of attributes and their types.
# -k key_schema -- JSON file path of a list of attributes and their key types.
#
# Returns:
# 0 - If successful.
# 1 - If it fails.
###############################################################################
function dynamodb_create_table() {
local table_name attribute_definitions key_schema response
local option OPTARG # Required to use getopts command in a function.
#######################################
# Function usage explanation
#######################################
function usage() {
echo "function dynamodb_create_table"
echo "Creates an Amazon DynamoDB table with on-demand billing."
echo " -n table_name -- The name of the table to create."
echo " -a attribute_definitions -- JSON file path of a list of attributes and their types."
echo " -k key_schema -- JSON file path of a list of attributes and their key types."
echo ""
}
# Retrieve the calling parameters.
while getopts "n:a:k:h" option; do
case "${option}" in
n) table_name="${OPTARG}" ;;
a) attribute_definitions="${OPTARG}" ;;
k) key_schema="${OPTARG}" ;;
h)
usage
return 0
;;
\?)
echo "Invalid parameter"
usage
return 1
;;
esac
done
export OPTIND=1
if [[ -z "$table_name" ]]; then
errecho "ERROR: You must provide a table name with the -n parameter."
usage
return 1
fi
if [[ -z "$attribute_definitions" ]]; then
errecho "ERROR: You must provide an attribute definitions json file path the -a parameter."
usage
return 1
fi
if [[ -z "$key_schema" ]]; then
errecho "ERROR: You must provide a key schema json file path the -k parameter."
usage
return 1
fi
iecho "Parameters:\n"
iecho " table_name: $table_name"
iecho " attribute_definitions: $attribute_definitions"
iecho " key_schema: $key_schema"
iecho ""
response=$(aws dynamodb create-table \
--table-name "$table_name" \
--attribute-definitions file://"$attribute_definitions" \
--billing-mode PAY_PER_REQUEST \
--key-schema file://"$key_schema" )
local error_code=${?}
if [[ $error_code -ne 0 ]]; then
aws_cli_error_log $error_code
errecho "ERROR: AWS reports create-table operation failed.$response"
return 1
fi
return 0
}
```
本示例中使用的实用程序函数。
```
###############################################################################
# function iecho
#
# This function enables the script to display the specified text only if
# the global variable $VERBOSE is set to true.
###############################################################################
function iecho() {
if [[ $VERBOSE == true ]]; then
echo "$@"
fi
}
###############################################################################
# function errecho
#
# This function outputs everything sent to it to STDERR (standard error output).
###############################################################################
function errecho() {
printf "%s\n" "$*" 1>&2
}
##############################################################################
# function aws_cli_error_log()
#
# This function is used to log the error messages from the AWS CLI.
#
# See https://docs.aws.amazon.com/cli/latest/topic/return-codes.html#cli-aws-help-return-codes.
#
# The function expects the following argument:
# $1 - The error code returned by the AWS CLI.
#
# Returns:
# 0: - Success.
#
##############################################################################
function aws_cli_error_log() {
local err_code=$1
errecho "Error code : $err_code"
if [ "$err_code" == 1 ]; then
errecho " One or more S3 transfers failed."
elif [ "$err_code" == 2 ]; then
errecho " Command line failed to parse."
elif [ "$err_code" == 130 ]; then
errecho " Process received SIGINT."
elif [ "$err_code" == 252 ]; then
errecho " Command syntax invalid."
elif [ "$err_code" == 253 ]; then
errecho " The system environment or configuration was invalid."
elif [ "$err_code" == 254 ]; then
errecho " The service returned an error."
elif [ "$err_code" == 255 ]; then
errecho " 255 is a catch-all error."
fi
return 0
}
```
+ 有关 API 详细信息，请参阅《AWS CLI 命令参考》**中的 [CreateTable](https://docs.aws.amazon.com/goto/aws-cli/dynamodb-2012-08-10/CreateTable)。
------
#### [ C\$1\$1 ]
**SDK for C\$1\$1**
查看 GitHub，了解更多信息。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/cpp/example_code/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
```
//! Create an Amazon DynamoDB table.
/*!
\sa createTable()
\param tableName: Name for the DynamoDB table.
\param primaryKey: Primary key for the DynamoDB table.
\param clientConfiguration: AWS client configuration.
\return bool: Function succeeded.
*/
bool AwsDoc::DynamoDB::createTable(const Aws::String &tableName,
const Aws::String &primaryKey,
const Aws::Client::ClientConfiguration &clientConfiguration) {
Aws::DynamoDB::DynamoDBClient dynamoClient(clientConfiguration);
std::cout << "Creating table " << tableName <<
" with a simple primary key: \"" << primaryKey << "\"." << std::endl;
Aws::DynamoDB::Model::CreateTableRequest request;
Aws::DynamoDB::Model::AttributeDefinition hashKey;
hashKey.SetAttributeName(primaryKey);
hashKey.SetAttributeType(Aws::DynamoDB::Model::ScalarAttributeType::S);
request.AddAttributeDefinitions(hashKey);
Aws::DynamoDB::Model::KeySchemaElement keySchemaElement;
keySchemaElement.WithAttributeName(primaryKey).WithKeyType(
Aws::DynamoDB::Model::KeyType::HASH);
request.AddKeySchema(keySchemaElement);
Aws::DynamoDB::Model::ProvisionedThroughput throughput;
throughput.WithReadCapacityUnits(5).WithWriteCapacityUnits(5);
request.SetProvisionedThroughput(throughput);
request.SetTableName(tableName);
const Aws::DynamoDB::Model::CreateTableOutcome &outcome = dynamoClient.CreateTable(
request);
if (outcome.IsSuccess()) {
std::cout << "Table \""
<< outcome.GetResult().GetTableDescription().GetTableName() <<
" created!" << std::endl;
}
else {
std::cerr << "Failed to create table: " << outcome.GetError().GetMessage()
<< std::endl;
return false;
}
return waitTableActive(tableName, dynamoClient);
}
```
等待表变为活动状态的代码。
```
//! Query a newly created DynamoDB table until it is active.
/*!
\sa waitTableActive()
\param waitTableActive: The DynamoDB table's name.
\param dynamoClient: A DynamoDB client.
\return bool: Function succeeded.
*/
bool AwsDoc::DynamoDB::waitTableActive(const Aws::String &tableName,
const Aws::DynamoDB::DynamoDBClient &dynamoClient) {
// Repeatedly call DescribeTable until table is ACTIVE.
const int MAX_QUERIES = 20;
Aws::DynamoDB::Model::DescribeTableRequest request;
request.SetTableName(tableName);
int count = 0;
while (count < MAX_QUERIES) {
const Aws::DynamoDB::Model::DescribeTableOutcome &result = dynamoClient.DescribeTable(
request);
if (result.IsSuccess()) {
Aws::DynamoDB::Model::TableStatus status = result.GetResult().GetTable().GetTableStatus();
if (Aws::DynamoDB::Model::TableStatus::ACTIVE != status) {
std::this_thread::sleep_for(std::chrono::seconds(1));
}
else {
return true;
}
}
else {
std::cerr << "Error DynamoDB::waitTableActive "
<< result.GetError().GetMessage() << std::endl;
return false;
}
count++;
}
return false;
}
```
+ 有关 API 详细信息，请参阅《适用于 C\$1\$1 的 AWS SDK API Reference》**中的 [CreateTable](https://docs.aws.amazon.com/goto/SdkForCpp/dynamodb-2012-08-10/CreateTable)。
------
#### [ CLI ]
**AWS CLI**
**示例 1：创建带标签的表**
以下 `create-table` 示例使用指定的属性和键架构创建名为 `MusicCollection` 的表。此表使用预调配的吞吐量，并使用 AWS 默认拥有的 CMK 进行静态加密。该命令还将标签应用于该表，其键为 `Owner`，值为 `blueTeam`。
```
aws dynamodb create-table \
--table-name MusicCollection \
--attribute-definitions AttributeName=Artist,AttributeType=S AttributeName=SongTitle,AttributeType=S \
--key-schema AttributeName=Artist,KeyType=HASH AttributeName=SongTitle,KeyType=RANGE \
--provisioned-throughput ReadCapacityUnits=5,WriteCapacityUnits=5 \
--tags Key=Owner,Value=blueTeam
```
输出：
```
{
"TableDescription": {
"AttributeDefinitions": [
{
"AttributeName": "Artist",
"AttributeType": "S"
},
{
"AttributeName": "SongTitle",
"AttributeType": "S"
}
],
"ProvisionedThroughput": {
"NumberOfDecreasesToday": 0,
"WriteCapacityUnits": 5,
"ReadCapacityUnits": 5
},
"TableSizeBytes": 0,
"TableName": "MusicCollection",
"TableStatus": "CREATING",
"KeySchema": [
{
"KeyType": "HASH",
"AttributeName": "Artist"
},
{
"KeyType": "RANGE",
"AttributeName": "SongTitle"
}
],
"ItemCount": 0,
"CreationDateTime": "2020-05-26T16:04:41.627000-07:00",
"TableArn": "arn:aws:dynamodb:us-west-2:123456789012:table/MusicCollection",
"TableId": "a1b2c3d4-5678-90ab-cdef-EXAMPLE11111"
}
}
```
有关更多信息，请参阅《Amazon DynamoDB 开发人员指南》**中的[表的基本操作](https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/WorkingWithTables.Basics.html)。
**示例 2：在按需模式下创建表**
以下示例使用按需模式（而不是预调配吞吐量模式）创建名为 `MusicCollection` 的表。这对于工作负载不可预测的表很有用。
```
aws dynamodb create-table \
--table-name MusicCollection \
--attribute-definitions AttributeName=Artist,AttributeType=S AttributeName=SongTitle,AttributeType=S \
--key-schema AttributeName=Artist,KeyType=HASH AttributeName=SongTitle,KeyType=RANGE \
--billing-mode PAY_PER_REQUEST
```
输出：
```
{
"TableDescription": {
"AttributeDefinitions": [
{
"AttributeName": "Artist",
"AttributeType": "S"
},
{
"AttributeName": "SongTitle",
"AttributeType": "S"
}
],
"TableName": "MusicCollection",
"KeySchema": [
{
"AttributeName": "Artist",
"KeyType": "HASH"
},
{
"AttributeName": "SongTitle",
"KeyType": "RANGE"
}
],
"TableStatus": "CREATING",
"CreationDateTime": "2020-05-27T11:44:10.807000-07:00",
"ProvisionedThroughput": {
"NumberOfDecreasesToday": 0,
"ReadCapacityUnits": 0,
"WriteCapacityUnits": 0
},
"TableSizeBytes": 0,
"ItemCount": 0,
"TableArn": "arn:aws:dynamodb:us-west-2:123456789012:table/MusicCollection",
"TableId": "a1b2c3d4-5678-90ab-cdef-EXAMPLE11111",
"BillingModeSummary": {
"BillingMode": "PAY_PER_REQUEST"
}
}
}
```
有关更多信息，请参阅《Amazon DynamoDB 开发人员指南》**中的[表的基本操作](https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/WorkingWithTables.Basics.html)。
**示例 3：创建表并使用客户托管的 CMK 对其进行加密**
以下示例创建一个名为 `MusicCollection` 的表并使用客户托管的 CMK 对其进行加密。
```
aws dynamodb create-table \
--table-name MusicCollection \
--attribute-definitions AttributeName=Artist,AttributeType=S AttributeName=SongTitle,AttributeType=S \
--key-schema AttributeName=Artist,KeyType=HASH AttributeName=SongTitle,KeyType=RANGE \
--provisioned-throughput ReadCapacityUnits=5,WriteCapacityUnits=5 \
--sse-specification Enabled=true,SSEType=KMS,KMSMasterKeyId=abcd1234-abcd-1234-a123-ab1234a1b234
```
输出：
```
{
"TableDescription": {
"AttributeDefinitions": [
{
"AttributeName": "Artist",
"AttributeType": "S"
},
{
"AttributeName": "SongTitle",
"AttributeType": "S"
}
],
"TableName": "MusicCollection",
"KeySchema": [
{
"AttributeName": "Artist",
"KeyType": "HASH"
},
{
"AttributeName": "SongTitle",
"KeyType": "RANGE"
}
],
"TableStatus": "CREATING",
"CreationDateTime": "2020-05-27T11:12:16.431000-07:00",
"ProvisionedThroughput": {
"NumberOfDecreasesToday": 0,
"ReadCapacityUnits": 5,
"WriteCapacityUnits": 5
},
"TableSizeBytes": 0,
"ItemCount": 0,
"TableArn": "arn:aws:dynamodb:us-west-2:123456789012:table/MusicCollection",
"TableId": "a1b2c3d4-5678-90ab-cdef-EXAMPLE11111",
"SSEDescription": {
"Status": "ENABLED",
"SSEType": "KMS",
"KMSMasterKeyArn": "arn:aws:kms:us-west-2:123456789012:key/abcd1234-abcd-1234-a123-ab1234a1b234"
}
}
}
```
有关更多信息，请参阅《Amazon DynamoDB 开发人员指南》**中的[表的基本操作](https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/WorkingWithTables.Basics.html)。
**示例 4：创建具有本地二级索引的表**
以下示例使用指定的属性和键架构来创建名为 `MusicCollection` 且其本地二级索引名为 `AlbumTitleIndex` 的表。
```
aws dynamodb create-table \
--table-name MusicCollection \
--attribute-definitions AttributeName=Artist,AttributeType=S AttributeName=SongTitle,AttributeType=S AttributeName=AlbumTitle,AttributeType=S \
--key-schema AttributeName=Artist,KeyType=HASH AttributeName=SongTitle,KeyType=RANGE \
--provisioned-throughput ReadCapacityUnits=10,WriteCapacityUnits=5 \
--local-secondary-indexes \
"[
{
\"IndexName\": \"AlbumTitleIndex\",
\"KeySchema\": [
{\"AttributeName\": \"Artist\",\"KeyType\":\"HASH\"},
{\"AttributeName\": \"AlbumTitle\",\"KeyType\":\"RANGE\"}
],
\"Projection\": {
\"ProjectionType\": \"INCLUDE\",
\"NonKeyAttributes\": [\"Genre\", \"Year\"]
}
}
]"
```
输出：
```
{
"TableDescription": {
"AttributeDefinitions": [
{
"AttributeName": "AlbumTitle",
"AttributeType": "S"
},
{
"AttributeName": "Artist",
"AttributeType": "S"
},
{
"AttributeName": "SongTitle",
"AttributeType": "S"
}
],
"TableName": "MusicCollection",
"KeySchema": [
{
"AttributeName": "Artist",
"KeyType": "HASH"
},
{
"AttributeName": "SongTitle",
"KeyType": "RANGE"
}
],
"TableStatus": "CREATING",
"CreationDateTime": "2020-05-26T15:59:49.473000-07:00",
"ProvisionedThroughput": {
"NumberOfDecreasesToday": 0,
"ReadCapacityUnits": 10,
"WriteCapacityUnits": 5
},
"TableSizeBytes": 0,
"ItemCount": 0,
"TableArn": "arn:aws:dynamodb:us-west-2:123456789012:table/MusicCollection",
"TableId": "a1b2c3d4-5678-90ab-cdef-EXAMPLE11111",
"LocalSecondaryIndexes": [
{
"IndexName": "AlbumTitleIndex",
"KeySchema": [
{
"AttributeName": "Artist",
"KeyType": "HASH"
},
{
"AttributeName": "AlbumTitle",
"KeyType": "RANGE"
}
],
"Projection": {
"ProjectionType": "INCLUDE",
"NonKeyAttributes": [
"Genre",
"Year"
]
},
"IndexSizeBytes": 0,
"ItemCount": 0,
"IndexArn": "arn:aws:dynamodb:us-west-2:123456789012:table/MusicCollection/index/AlbumTitleIndex"
}
]
}
}
```
有关更多信息，请参阅《Amazon DynamoDB 开发人员指南》**中的[表的基本操作](https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/WorkingWithTables.Basics.html)。
**示例 5：创建具有全局二级索引的表**
以下示例创建一个名为 `GameScores` 且其全局二级索引名为 `GameTitleIndex` 的表。基表的分区键为 `UserId`，排序键为 `GameTitle`，可以有效地找到特定游戏的单个用户的最佳分数，而 GSI 则具有分区键 `GameTitle` 和排序键 `TopScore`，允许您快速找到特定游戏的总体最高分。
```
aws dynamodb create-table \
--table-name GameScores \
--attribute-definitions AttributeName=UserId,AttributeType=S AttributeName=GameTitle,AttributeType=S AttributeName=TopScore,AttributeType=N \
--key-schema AttributeName=UserId,KeyType=HASH \
AttributeName=GameTitle,KeyType=RANGE \
--provisioned-throughput ReadCapacityUnits=10,WriteCapacityUnits=5 \
--global-secondary-indexes \
"[
{
\"IndexName\": \"GameTitleIndex\",
\"KeySchema\": [
{\"AttributeName\":\"GameTitle\",\"KeyType\":\"HASH\"},
{\"AttributeName\":\"TopScore\",\"KeyType\":\"RANGE\"}
],
\"Projection\": {
\"ProjectionType\":\"INCLUDE\",
\"NonKeyAttributes\":[\"UserId\"]
},
\"ProvisionedThroughput\": {
\"ReadCapacityUnits\": 10,
\"WriteCapacityUnits\": 5
}
}
]"
```
输出：
```
{
"TableDescription": {
"AttributeDefinitions": [
{
"AttributeName": "GameTitle",
"AttributeType": "S"
},
{
"AttributeName": "TopScore",
"AttributeType": "N"
},
{
"AttributeName": "UserId",
"AttributeType": "S"
}
],
"TableName": "GameScores",
"KeySchema": [
{
"AttributeName": "UserId",
"KeyType": "HASH"
},
{
"AttributeName": "GameTitle",
"KeyType": "RANGE"
}
],
"TableStatus": "CREATING",
"CreationDateTime": "2020-05-26T17:28:15.602000-07:00",
"ProvisionedThroughput": {
"NumberOfDecreasesToday": 0,
"ReadCapacityUnits": 10,
"WriteCapacityUnits": 5
},
"TableSizeBytes": 0,
"ItemCount": 0,
"TableArn": "arn:aws:dynamodb:us-west-2:123456789012:table/GameScores",
"TableId": "a1b2c3d4-5678-90ab-cdef-EXAMPLE11111",
"GlobalSecondaryIndexes": [
{
"IndexName": "GameTitleIndex",
"KeySchema": [
{
"AttributeName": "GameTitle",
"KeyType": "HASH"
},
{
"AttributeName": "TopScore",
"KeyType": "RANGE"
}
],
"Projection": {
"ProjectionType": "INCLUDE",
"NonKeyAttributes": [
"UserId"
]
},
"IndexStatus": "CREATING",
"ProvisionedThroughput": {
"NumberOfDecreasesToday": 0,
"ReadCapacityUnits": 10,
"WriteCapacityUnits": 5
},
"IndexSizeBytes": 0,
"ItemCount": 0,
"IndexArn": "arn:aws:dynamodb:us-west-2:123456789012:table/GameScores/index/GameTitleIndex"
}
]
}
}
```
有关更多信息，请参阅《Amazon DynamoDB 开发人员指南》**中的[表的基本操作](https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/WorkingWithTables.Basics.html)。
**示例 6：一次创建一个具有多个全局二级索引的表**
以下示例创建一个名为 `GameScores` 且具有两个全局二级索引的表。GSI 架构通过文件传递，而不是通过命令行传递。
```
aws dynamodb create-table \
--table-name GameScores \
--attribute-definitions AttributeName=UserId,AttributeType=S AttributeName=GameTitle,AttributeType=S AttributeName=TopScore,AttributeType=N AttributeName=Date,AttributeType=S \
--key-schema AttributeName=UserId,KeyType=HASH AttributeName=GameTitle,KeyType=RANGE \
--provisioned-throughput ReadCapacityUnits=10,WriteCapacityUnits=5 \
--global-secondary-indexes file://gsi.json
```
的内容`gsi.json`：
```
[
{
"IndexName": "GameTitleIndex",
"KeySchema": [
{
"AttributeName": "GameTitle",
"KeyType": "HASH"
},
{
"AttributeName": "TopScore",
"KeyType": "RANGE"
}
],
"Projection": {
"ProjectionType": "ALL"
},
"ProvisionedThroughput": {
"ReadCapacityUnits": 10,
"WriteCapacityUnits": 5
}
},
{
"IndexName": "GameDateIndex",
"KeySchema": [
{
"AttributeName": "GameTitle",
"KeyType": "HASH"
},
{
"AttributeName": "Date",
"KeyType": "RANGE"
}
],
"Projection": {
"ProjectionType": "ALL"
},
"ProvisionedThroughput": {
"ReadCapacityUnits": 5,
"WriteCapacityUnits": 5
}
}
]
```
输出：
```
{
"TableDescription": {
"AttributeDefinitions": [
{
"AttributeName": "Date",
"AttributeType": "S"
},
{
"AttributeName": "GameTitle",
"AttributeType": "S"
},
{
"AttributeName": "TopScore",
"AttributeType": "N"
},
{
"AttributeName": "UserId",
"AttributeType": "S"
}
],
"TableName": "GameScores",
"KeySchema": [
{
"AttributeName": "UserId",
"KeyType": "HASH"
},
{
"AttributeName": "GameTitle",
"KeyType": "RANGE"
}
],
"TableStatus": "CREATING",
"CreationDateTime": "2020-08-04T16:40:55.524000-07:00",
"ProvisionedThroughput": {
"NumberOfDecreasesToday": 0,
"ReadCapacityUnits": 10,
"WriteCapacityUnits": 5
},
"TableSizeBytes": 0,
"ItemCount": 0,
"TableArn": "arn:aws:dynamodb:us-west-2:123456789012:table/GameScores",
"TableId": "a1b2c3d4-5678-90ab-cdef-EXAMPLE11111",
"GlobalSecondaryIndexes": [
{
"IndexName": "GameTitleIndex",
"KeySchema": [
{
"AttributeName": "GameTitle",
"KeyType": "HASH"
},
{
"AttributeName": "TopScore",
"KeyType": "RANGE"
}
],
"Projection": {
"ProjectionType": "ALL"
},
"IndexStatus": "CREATING",
"ProvisionedThroughput": {
"NumberOfDecreasesToday": 0,
"ReadCapacityUnits": 10,
"WriteCapacityUnits": 5
},
"IndexSizeBytes": 0,
"ItemCount": 0,
"IndexArn": "arn:aws:dynamodb:us-west-2:123456789012:table/GameScores/index/GameTitleIndex"
},
{
"IndexName": "GameDateIndex",
"KeySchema": [
{
"AttributeName": "GameTitle",
"KeyType": "HASH"
},
{
"AttributeName": "Date",
"KeyType": "RANGE"
}
],
"Projection": {
"ProjectionType": "ALL"
},
"IndexStatus": "CREATING",
"ProvisionedThroughput": {
"NumberOfDecreasesToday": 0,
"ReadCapacityUnits": 5,
"WriteCapacityUnits": 5
},
"IndexSizeBytes": 0,
"ItemCount": 0,
"IndexArn": "arn:aws:dynamodb:us-west-2:123456789012:table/GameScores/index/GameDateIndex"
}
]
}
}
```
有关更多信息，请参阅《Amazon DynamoDB 开发人员指南》**中的[表的基本操作](https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/WorkingWithTables.Basics.html)。
**示例 7：创建启用了 Streams 的表**
以下示例创建一个名为 `GameScores` 且启用了 DynamoDB Streams 的表。每个项的新旧映像都将写入流中。
```
aws dynamodb create-table \
--table-name GameScores \
--attribute-definitions AttributeName=UserId,AttributeType=S AttributeName=GameTitle,AttributeType=S \
--key-schema AttributeName=UserId,KeyType=HASH AttributeName=GameTitle,KeyType=RANGE \
--provisioned-throughput ReadCapacityUnits=10,WriteCapacityUnits=5 \
--stream-specification StreamEnabled=TRUE,StreamViewType=NEW_AND_OLD_IMAGES
```
输出：
```
{
"TableDescription": {
"AttributeDefinitions": [
{
"AttributeName": "GameTitle",
"AttributeType": "S"
},
{
"AttributeName": "UserId",
"AttributeType": "S"
}
],
"TableName": "GameScores",
"KeySchema": [
{
"AttributeName": "UserId",
"KeyType": "HASH"
},
{
"AttributeName": "GameTitle",
"KeyType": "RANGE"
}
],
"TableStatus": "CREATING",
"CreationDateTime": "2020-05-27T10:49:34.056000-07:00",
"ProvisionedThroughput": {
"NumberOfDecreasesToday": 0,
"ReadCapacityUnits": 10,
"WriteCapacityUnits": 5
},
"TableSizeBytes": 0,
"ItemCount": 0,
"TableArn": "arn:aws:dynamodb:us-west-2:123456789012:table/GameScores",
"TableId": "a1b2c3d4-5678-90ab-cdef-EXAMPLE11111",
"StreamSpecification": {
"StreamEnabled": true,
"StreamViewType": "NEW_AND_OLD_IMAGES"
},
"LatestStreamLabel": "2020-05-27T17:49:34.056",
"LatestStreamArn": "arn:aws:dynamodb:us-west-2:123456789012:table/GameScores/stream/2020-05-27T17:49:34.056"
}
}
```
有关更多信息，请参阅《Amazon DynamoDB 开发人员指南》**中的[表的基本操作](https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/WorkingWithTables.Basics.html)。
**示例 8：创建启用了 Keys-Only Stream 的表**
以下示例将创建一个名为 `GameScores` 且启用了 DynamoDB Streams 的表。仅将所修改项的键属性写入流中。
```
aws dynamodb create-table \
--table-name GameScores \
--attribute-definitions AttributeName=UserId,AttributeType=S AttributeName=GameTitle,AttributeType=S \
--key-schema AttributeName=UserId,KeyType=HASH AttributeName=GameTitle,KeyType=RANGE \
--provisioned-throughput ReadCapacityUnits=10,WriteCapacityUnits=5 \
--stream-specification StreamEnabled=TRUE,StreamViewType=KEYS_ONLY
```
输出：
```
{
"TableDescription": {
"AttributeDefinitions": [
{
"AttributeName": "GameTitle",
"AttributeType": "S"
},
{
"AttributeName": "UserId",
"AttributeType": "S"
}
],
"TableName": "GameScores",
"KeySchema": [
{
"AttributeName": "UserId",
"KeyType": "HASH"
},
{
"AttributeName": "GameTitle",
"KeyType": "RANGE"
}
],
"TableStatus": "CREATING",
"CreationDateTime": "2023-05-25T18:45:34.140000+00:00",
"ProvisionedThroughput": {
"NumberOfDecreasesToday": 0,
"ReadCapacityUnits": 10,
"WriteCapacityUnits": 5
},
"TableSizeBytes": 0,
"ItemCount": 0,
"TableArn": "arn:aws:dynamodb:us-west-2:123456789012:table/GameScores",
"TableId": "a1b2c3d4-5678-90ab-cdef-EXAMPLE11111",
"StreamSpecification": {
"StreamEnabled": true,
"StreamViewType": "KEYS_ONLY"
},
"LatestStreamLabel": "2023-05-25T18:45:34.140",
"LatestStreamArn": "arn:aws:dynamodb:us-west-2:123456789012:table/GameScores/stream/2023-05-25T18:45:34.140",
"DeletionProtectionEnabled": false
}
}
```
有关更多信息，请参阅《Amazon DynamoDB 开发人员指南》**中的[更改 DynamoDB Streams 的数据捕获](https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/Streams.html)。
**示例 9：使用 Standard Infrequent Access 类创建表**
以下示例创建名为 `GameScores` 的表并分配 Standard-Infrequent Access（DynamoDB 标准-IA）表类。此表类针对主要的存储成本进行了优化。
```
aws dynamodb create-table \
--table-name GameScores \
--attribute-definitions AttributeName=UserId,AttributeType=S AttributeName=GameTitle,AttributeType=S \
--key-schema AttributeName=UserId,KeyType=HASH AttributeName=GameTitle,KeyType=RANGE \
--provisioned-throughput ReadCapacityUnits=10,WriteCapacityUnits=5 \
--table-class STANDARD_INFREQUENT_ACCESS
```
输出：
```
{
"TableDescription": {
"AttributeDefinitions": [
{
"AttributeName": "GameTitle",
"AttributeType": "S"
},
{
"AttributeName": "UserId",
"AttributeType": "S"
}
],
"TableName": "GameScores",
"KeySchema": [
{
"AttributeName": "UserId",
"KeyType": "HASH"
},
{
"AttributeName": "GameTitle",
"KeyType": "RANGE"
}
],
"TableStatus": "CREATING",
"CreationDateTime": "2023-05-25T18:33:07.581000+00:00",
"ProvisionedThroughput": {
"NumberOfDecreasesToday": 0,
"ReadCapacityUnits": 10,
"WriteCapacityUnits": 5
},
"TableSizeBytes": 0,
"ItemCount": 0,
"TableArn": "arn:aws:dynamodb:us-west-2:123456789012:table/GameScores",
"TableId": "a1b2c3d4-5678-90ab-cdef-EXAMPLE11111",
"TableClassSummary": {
"TableClass": "STANDARD_INFREQUENT_ACCESS"
},
"DeletionProtectionEnabled": false
}
}
```
有关更多信息，请参阅《Amazon DynamoDB 开发人员指南》**中的[表类](https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/HowItWorks.TableClasses.html)。
**示例 10：创建启用了删除保护功能的表**
以下示例创建一个名为 `GameScores` 的表并启用删除保护。
```
aws dynamodb create-table \
--table-name GameScores \
--attribute-definitions AttributeName=UserId,AttributeType=S AttributeName=GameTitle,AttributeType=S \
--key-schema AttributeName=UserId,KeyType=HASH AttributeName=GameTitle,KeyType=RANGE \
--provisioned-throughput ReadCapacityUnits=10,WriteCapacityUnits=5 \
--deletion-protection-enabled
```
输出：
```
{
"TableDescription": {
"AttributeDefinitions": [
{
"AttributeName": "GameTitle",
"AttributeType": "S"
},
{
"AttributeName": "UserId",
"AttributeType": "S"
}
],
"TableName": "GameScores",
"KeySchema": [
{
"AttributeName": "UserId",
"KeyType": "HASH"
},
{
"AttributeName": "GameTitle",
"KeyType": "RANGE"
}
],
"TableStatus": "CREATING",
"CreationDateTime": "2023-05-25T23:02:17.093000+00:00",
"ProvisionedThroughput": {
"NumberOfDecreasesToday": 0,
"ReadCapacityUnits": 10,
"WriteCapacityUnits": 5
},
"TableSizeBytes": 0,
"ItemCount": 0,
"TableArn": "arn:aws:dynamodb:us-west-2:123456789012:table/GameScores",
"TableId": "a1b2c3d4-5678-90ab-cdef-EXAMPLE11111",
"DeletionProtectionEnabled": true
}
}
```
有关更多信息，请参阅《Amazon DynamoDB 开发人员指南》**中的[使用删除保护](https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/WorkingWithTables.Basics.html#WorkingWithTables.Basics.DeletionProtection)。
+ 有关 API 详细信息，请参阅《AWS CLI 命令参考》**中的 [CreateTable](https://awscli.amazonaws.com/v2/documentation/api/latest/reference/dynamodb/create-table.html)。
------
#### [ Go ]
**适用于 Go 的 SDK V2**
查看 GitHub，了解更多信息。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/gov2/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
```
import (
"context"
"errors"
"log"
"time"
"github.com/aws/aws-sdk-go-v2/aws"
"github.com/aws/aws-sdk-go-v2/feature/dynamodb/attributevalue"
"github.com/aws/aws-sdk-go-v2/feature/dynamodb/expression"
"github.com/aws/aws-sdk-go-v2/service/dynamodb"
"github.com/aws/aws-sdk-go-v2/service/dynamodb/types"
)
// TableBasics encapsulates the Amazon DynamoDB service actions used in the examples.
// It contains a DynamoDB service client that is used to act on the specified table.
type TableBasics struct {
DynamoDbClient *dynamodb.Client
TableName string
}
// CreateMovieTable creates a DynamoDB table with a composite primary key defined as
// a string sort key named `title`, and a numeric partition key named `year`.
// This function uses NewTableExistsWaiter to wait for the table to be created by
// DynamoDB before it returns.
func (basics TableBasics) CreateMovieTable(ctx context.Context) (*types.TableDescription, error) {
var tableDesc *types.TableDescription
table, err := basics.DynamoDbClient.CreateTable(ctx, &dynamodb.CreateTableInput{
AttributeDefinitions: []types.AttributeDefinition{{
AttributeName: aws.String("year"),
AttributeType: types.ScalarAttributeTypeN,
}, {
AttributeName: aws.String("title"),
AttributeType: types.ScalarAttributeTypeS,
}},
KeySchema: []types.KeySchemaElement{{
AttributeName: aws.String("year"),
KeyType: types.KeyTypeHash,
}, {
AttributeName: aws.String("title"),
KeyType: types.KeyTypeRange,
}},
TableName: aws.String(basics.TableName),
BillingMode: types.BillingModePayPerRequest,
})
if err != nil {
log.Printf("Couldn't create table %v. Here's why: %v\n", basics.TableName, err)
} else {
waiter := dynamodb.NewTableExistsWaiter(basics.DynamoDbClient)
err = waiter.Wait(ctx, &dynamodb.DescribeTableInput{
TableName: aws.String(basics.TableName)}, 5*time.Minute)
if err != nil {
log.Printf("Wait for table exists failed. Here's why: %v\n", err)
}
tableDesc = table.TableDescription
log.Printf("Ccreating table test")
}
return tableDesc, err
}
```
+ 有关 API 详细信息，请参阅《适用于 Go 的 AWS SDK API Reference》**中的 [CreateTable](https://pkg.go.dev/github.com/aws/aws-sdk-go-v2/service/dynamodb#Client.CreateTable)。
------
#### [ Java ]
**适用于 Java 的 SDK 2.x**
查看 GitHub，了解更多信息。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javav2/example_code/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
```
import software.amazon.awssdk.core.waiters.WaiterResponse;
import software.amazon.awssdk.regions.Region;
import software.amazon.awssdk.services.dynamodb.DynamoDbClient;
import software.amazon.awssdk.services.dynamodb.model.AttributeDefinition;
import software.amazon.awssdk.services.dynamodb.model.BillingMode;
import software.amazon.awssdk.services.dynamodb.model.CreateTableRequest;
import software.amazon.awssdk.services.dynamodb.model.CreateTableResponse;
import software.amazon.awssdk.services.dynamodb.model.DescribeTableRequest;
import software.amazon.awssdk.services.dynamodb.model.DescribeTableResponse;
import software.amazon.awssdk.services.dynamodb.model.DynamoDbException;
import software.amazon.awssdk.services.dynamodb.model.KeySchemaElement;
import software.amazon.awssdk.services.dynamodb.model.KeyType;
import software.amazon.awssdk.services.dynamodb.model.OnDemandThroughput;
import software.amazon.awssdk.services.dynamodb.model.ProvisionedThroughput;
import software.amazon.awssdk.services.dynamodb.model.ScalarAttributeType;
import software.amazon.awssdk.services.dynamodb.waiters.DynamoDbWaiter;
/**
* Before running this Java V2 code example, set up your development
* environment, including your credentials.
*
* For more information, see the following documentation topic:
*
* https://docs.aws.amazon.com/sdk-for-java/latest/developer-guide/get-started.html
*/
public class CreateTable {
public static void main(String[] args) {
final String usage = """
Usage:
Where:
tableName - The Amazon DynamoDB table to create (for example, Music3).
key - The key for the Amazon DynamoDB table (for example, Artist).
""";
if (args.length != 2) {
System.out.println(usage);
System.exit(1);
}
String tableName = args[0];
String key = args[1];
System.out.println("Creating an Amazon DynamoDB table " + tableName + " with a simple primary key: " + key);
Region region = Region.US_EAST_1;
DynamoDbClient ddb = DynamoDbClient.builder()
.region(region)
.build();
String result = createTable(ddb, tableName, key);
System.out.println("New table is " + result);
ddb.close();
}
public static String createTable(DynamoDbClient ddb, String tableName, String key) {
DynamoDbWaiter dbWaiter = ddb.waiter();
CreateTableRequest request = CreateTableRequest.builder()
.attributeDefinitions(AttributeDefinition.builder()
.attributeName(key)
.attributeType(ScalarAttributeType.S)
.build())
.keySchema(KeySchemaElement.builder()
.attributeName(key)
.keyType(KeyType.HASH)
.build())
.billingMode(BillingMode.PAY_PER_REQUEST) // DynamoDB automatically scales based on traffic.
.tableName(tableName)
.build();
String newTable;
try {
CreateTableResponse response = ddb.createTable(request);
DescribeTableRequest tableRequest = DescribeTableRequest.builder()
.tableName(tableName)
.build();
// Wait until the Amazon DynamoDB table is created.
WaiterResponse waiterResponse = dbWaiter.waitUntilTableExists(tableRequest);
waiterResponse.matched().response().ifPresent(System.out::println);
newTable = response.tableDescription().tableName();
return newTable;
} catch (DynamoDbException e) {
System.err.println(e.getMessage());
System.exit(1);
}
return "";
}
}
```
+ 有关 API 详细信息，请参阅《AWS SDK for Java 2.x API Reference》**中的 [CreateTable](https://docs.aws.amazon.com/goto/SdkForJavaV2/dynamodb-2012-08-10/CreateTable)。
------
#### [ JavaScript ]
**SDK for JavaScript (v3)**
查看 GitHub，了解更多信息。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javascriptv3/example_code/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
```
import { CreateTableCommand, DynamoDBClient } from "@aws-sdk/client-dynamodb";
const client = new DynamoDBClient({});
export const main = async () => {
const command = new CreateTableCommand({
TableName: "EspressoDrinks",
// For more information about data types,
// see https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/HowItWorks.NamingRulesDataTypes.html#HowItWorks.DataTypes and
// https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/Programming.LowLevelAPI.html#Programming.LowLevelAPI.DataTypeDescriptors
AttributeDefinitions: [
{
AttributeName: "DrinkName",
AttributeType: "S",
},
],
KeySchema: [
{
AttributeName: "DrinkName",
KeyType: "HASH",
},
],
BillingMode: "PAY_PER_REQUEST",
});
const response = await client.send(command);
console.log(response);
return response;
};
```
+ 有关更多信息，请参阅《适用于 JavaScript 的 AWS SDK 开发人员指南》[https://docs.aws.amazon.com/sdk-for-javascript/v3/developer-guide/dynamodb-examples-using-tables.html#dynamodb-examples-using-tables-creating-a-table](https://docs.aws.amazon.com/sdk-for-javascript/v3/developer-guide/dynamodb-examples-using-tables.html#dynamodb-examples-using-tables-creating-a-table)。
+ 有关 API 详细信息，请参阅《适用于 JavaScript 的 AWS SDK API Reference》**中的 [CreateTable](https://docs.aws.amazon.com/AWSJavaScriptSDK/v3/latest/client/dynamodb/command/CreateTableCommand)。
**SDK for JavaScript (v2)**
查看 GitHub，了解更多信息。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javascript/example_code/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
```
// Load the AWS SDK for Node.js
var AWS = require("aws-sdk");
// Set the region
AWS.config.update({ region: "REGION" });
// Create the DynamoDB service object
var ddb = new AWS.DynamoDB({ apiVersion: "2012-08-10" });
var params = {
AttributeDefinitions: [
{
AttributeName: "CUSTOMER_ID",
AttributeType: "N",
},
{
AttributeName: "CUSTOMER_NAME",
AttributeType: "S",
},
],
KeySchema: [
{
AttributeName: "CUSTOMER_ID",
KeyType: "HASH",
},
{
AttributeName: "CUSTOMER_NAME",
KeyType: "RANGE",
},
],
ProvisionedThroughput: {
ReadCapacityUnits: 1,
WriteCapacityUnits: 1,
},
TableName: "CUSTOMER_LIST",
StreamSpecification: {
StreamEnabled: false,
},
};
// Call DynamoDB to create the table
ddb.createTable(params, function (err, data) {
if (err) {
console.log("Error", err);
} else {
console.log("Table Created", data);
}
});
```
+ 有关更多信息，请参阅《适用于 JavaScript 的 AWS SDK 开发人员指南》[https://docs.aws.amazon.com/sdk-for-javascript/v2/developer-guide/dynamodb-examples-using-tables.html#dynamodb-examples-using-tables-creating-a-table](https://docs.aws.amazon.com/sdk-for-javascript/v2/developer-guide/dynamodb-examples-using-tables.html#dynamodb-examples-using-tables-creating-a-table)。
+ 有关 API 详细信息，请参阅《适用于 JavaScript 的 AWS SDK API Reference》**中的 [CreateTable](https://docs.aws.amazon.com/goto/AWSJavaScriptSDK/dynamodb-2012-08-10/CreateTable)。
------
#### [ Kotlin ]
**SDK for Kotlin**
查看 GitHub，了解更多信息。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/kotlin/services/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
```
suspend fun createNewTable(
tableNameVal: String,
key: String,
): String? {
val attDef =
AttributeDefinition {
attributeName = key
attributeType = ScalarAttributeType.S
}
val keySchemaVal =
KeySchemaElement {
attributeName = key
keyType = KeyType.Hash
}
val request =
CreateTableRequest {
attributeDefinitions = listOf(attDef)
keySchema = listOf(keySchemaVal)
billingMode = BillingMode.PayPerRequest
tableName = tableNameVal
}
DynamoDbClient.fromEnvironment { region = "us-east-1" }.use { ddb ->
var tableArn: String
val response = ddb.createTable(request)
ddb.waitUntilTableExists {
// suspend call
tableName = tableNameVal
}
tableArn = response.tableDescription!!.tableArn.toString()
println("Table $tableArn is ready")
return tableArn
}
}
```
+ 有关 API 详细信息，请参阅《AWS SDK for Kotlin API Reference》**中的 [CreateTable](https://sdk.amazonaws.com/kotlin/api/latest/index.html)。
------
#### [ PHP ]
**适用于 PHP 的 SDK**
查看 GitHub，了解更多信息。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/php/example_code/dynamodb#code-examples) 中查找完整示例，了解如何进行设置和运行。
创建表。
```
$tableName = "ddb_demo_table_$uuid";
$service->createTable(
$tableName,
[
new DynamoDBAttribute('year', 'N', 'HASH'),
new DynamoDBAttribute('title', 'S', 'RANGE')
]
);
public function createTable(string $tableName, array $attributes)
{
$keySchema = [];
$attributeDefinitions = [];
foreach ($attributes as $attribute) {
if (is_a($attribute, DynamoDBAttribute::class)) {
$keySchema[] = ['AttributeName' => $attribute->AttributeName, 'KeyType' => $attribute->KeyType];
$attributeDefinitions[] =
['AttributeName' => $attribute->AttributeName, 'AttributeType' => $attribute->AttributeType];
}
}
$this->dynamoDbClient->createTable([
'TableName' => $tableName,
'KeySchema' => $keySchema,
'AttributeDefinitions' => $attributeDefinitions,
'ProvisionedThroughput' => ['ReadCapacityUnits' => 10, 'WriteCapacityUnits' => 10],
]);
}
```
+ 有关 API 详细信息，请参阅《适用于 PHP 的 AWS SDK API Reference》**中的 [CreateTable](https://docs.aws.amazon.com/goto/SdkForPHPV3/dynamodb-2012-08-10/CreateTable)。
------
#### [ PowerShell ]
**适用于 PowerShell V4 的工具**
**示例 1：此示例创建一个名为 Thread 的表，该表的主键由“ForumName”（键类型哈希）和“Subject”（键类型范围）组成。用于构造表的架构可以通过管道传输到所示的每个 cmdlet 中，也可以使用 -Schema 参数指定。**
```
$schema = New-DDBTableSchema
$schema | Add-DDBKeySchema -KeyName "ForumName" -KeyDataType "S"
$schema | Add-DDBKeySchema -KeyName "Subject" -KeyType RANGE -KeyDataType "S"
$schema | New-DDBTable -TableName "Thread" -ReadCapacity 10 -WriteCapacity 5
```
**输出：**
```
AttributeDefinitions : {ForumName, Subject}
TableName : Thread
KeySchema : {ForumName, Subject}
TableStatus : CREATING
CreationDateTime : 10/28/2013 4:39:49 PM
ProvisionedThroughput : Amazon.DynamoDBv2.Model.ProvisionedThroughputDescription
TableSizeBytes : 0
ItemCount : 0
LocalSecondaryIndexes : {}
```
**示例 2：此示例创建一个名为 Thread 的表，该表的主键由“ForumName”（键类型哈希）和“Subject”（键类型范围）组成。还定义了本地二级索引。本地二级索引的键将根据表上的主哈希键（ForumName）自动设置。用于构造表的架构可以通过管道传输到所示的每个 cmdlet 中，也可以使用 -Schema 参数指定。**
```
$schema = New-DDBTableSchema
$schema | Add-DDBKeySchema -KeyName "ForumName" -KeyDataType "S"
$schema | Add-DDBKeySchema -KeyName "Subject" -KeyDataType "S"
$schema | Add-DDBIndexSchema -IndexName "LastPostIndex" -RangeKeyName "LastPostDateTime" -RangeKeyDataType "S" -ProjectionType "keys_only"
$schema | New-DDBTable -TableName "Thread" -ReadCapacity 10 -WriteCapacity 5
```
**输出：**
```
AttributeDefinitions : {ForumName, LastPostDateTime, Subject}
TableName : Thread
KeySchema : {ForumName, Subject}
TableStatus : CREATING
CreationDateTime : 10/28/2013 4:39:49 PM
ProvisionedThroughput : Amazon.DynamoDBv2.Model.ProvisionedThroughputDescription
TableSizeBytes : 0
ItemCount : 0
LocalSecondaryIndexes : {LastPostIndex}
```
**示例 3：此示例展示了如何使用单个管道创建一个名为 Thread 的表，该表的主键由“ForumName”（键类型哈希）和“Subject”（键类型范围）以及本地二级索引组成。如果管道或 -Schema 参数中未提供 TableSchema 对象，则 Add-DDBKeySchema 和 Add-DDBIndexSchema 会为您创建一个新的 TableSchema 对象。**
```
New-DDBTableSchema |
Add-DDBKeySchema -KeyName "ForumName" -KeyDataType "S" |
Add-DDBKeySchema -KeyName "Subject" -KeyDataType "S" |
Add-DDBIndexSchema -IndexName "LastPostIndex" `
-RangeKeyName "LastPostDateTime" `
-RangeKeyDataType "S" `
-ProjectionType "keys_only" |
New-DDBTable -TableName "Thread" -ReadCapacity 10 -WriteCapacity 5
```
**输出：**
```
AttributeDefinitions : {ForumName, LastPostDateTime, Subject}
TableName : Thread
KeySchema : {ForumName, Subject}
TableStatus : CREATING
CreationDateTime : 10/28/2013 4:39:49 PM
ProvisionedThroughput : Amazon.DynamoDBv2.Model.ProvisionedThroughputDescription
TableSizeBytes : 0
ItemCount : 0
LocalSecondaryIndexes : {LastPostIndex}
```
+ 有关 API 详细信息，请参阅《AWS Tools for PowerShell Cmdlet Reference (V4)》**中的 [CreateTable](https://docs.aws.amazon.com/powershell/v4/reference)。
**适用于 PowerShell V5 的工具**
**示例 1：此示例创建一个名为 Thread 的表，该表的主键由“ForumName”（键类型哈希）和“Subject”（键类型范围）组成。用于构造表的架构可以通过管道传输到所示的每个 cmdlet 中，也可以使用 -Schema 参数指定。**
```
$schema = New-DDBTableSchema
$schema | Add-DDBKeySchema -KeyName "ForumName" -KeyDataType "S"
$schema | Add-DDBKeySchema -KeyName "Subject" -KeyType RANGE -KeyDataType "S"
$schema | New-DDBTable -TableName "Thread" -ReadCapacity 10 -WriteCapacity 5
```
**输出：**
```
AttributeDefinitions : {ForumName, Subject}
TableName : Thread
KeySchema : {ForumName, Subject}
TableStatus : CREATING
CreationDateTime : 10/28/2013 4:39:49 PM
ProvisionedThroughput : Amazon.DynamoDBv2.Model.ProvisionedThroughputDescription
TableSizeBytes : 0
ItemCount : 0
LocalSecondaryIndexes : {}
```
**示例 2：此示例创建一个名为 Thread 的表，该表的主键由“ForumName”（键类型哈希）和“Subject”（键类型范围）组成。还定义了本地二级索引。本地二级索引的键将根据表上的主哈希键（ForumName）自动设置。用于构造表的架构可以通过管道传输到所示的每个 cmdlet 中，也可以使用 -Schema 参数指定。**
```
$schema = New-DDBTableSchema
$schema | Add-DDBKeySchema -KeyName "ForumName" -KeyDataType "S"
$schema | Add-DDBKeySchema -KeyName "Subject" -KeyDataType "S"
$schema | Add-DDBIndexSchema -IndexName "LastPostIndex" -RangeKeyName "LastPostDateTime" -RangeKeyDataType "S" -ProjectionType "keys_only"
$schema | New-DDBTable -TableName "Thread" -ReadCapacity 10 -WriteCapacity 5
```
**输出：**
```
AttributeDefinitions : {ForumName, LastPostDateTime, Subject}
TableName : Thread
KeySchema : {ForumName, Subject}
TableStatus : CREATING
CreationDateTime : 10/28/2013 4:39:49 PM
ProvisionedThroughput : Amazon.DynamoDBv2.Model.ProvisionedThroughputDescription
TableSizeBytes : 0
ItemCount : 0
LocalSecondaryIndexes : {LastPostIndex}
```
**示例 3：此示例展示了如何使用单个管道创建一个名为 Thread 的表，该表的主键由“ForumName”（键类型哈希）和“Subject”（键类型范围）以及本地二级索引组成。如果管道或 -Schema 参数中未提供 TableSchema 对象，则 Add-DDBKeySchema 和 Add-DDBIndexSchema 会为您创建一个新的 TableSchema 对象。**
```
New-DDBTableSchema |
Add-DDBKeySchema -KeyName "ForumName" -KeyDataType "S" |
Add-DDBKeySchema -KeyName "Subject" -KeyDataType "S" |
Add-DDBIndexSchema -IndexName "LastPostIndex" `
-RangeKeyName "LastPostDateTime" `
-RangeKeyDataType "S" `
-ProjectionType "keys_only" |
New-DDBTable -TableName "Thread" -ReadCapacity 10 -WriteCapacity 5
```
**输出：**
```
AttributeDefinitions : {ForumName, LastPostDateTime, Subject}
TableName : Thread
KeySchema : {ForumName, Subject}
TableStatus : CREATING
CreationDateTime : 10/28/2013 4:39:49 PM
ProvisionedThroughput : Amazon.DynamoDBv2.Model.ProvisionedThroughputDescription
TableSizeBytes : 0
ItemCount : 0
LocalSecondaryIndexes : {LastPostIndex}
```
+ 有关 API 详细信息，请参阅《AWS Tools for PowerShell Cmdlet Reference (V5)》**中的 [CreateTable](https://docs.aws.amazon.com/powershell/v5/reference)。
------
#### [ Python ]
**适用于 Python 的 SDK（Boto3）**
查看 GitHub，了解更多信息。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/python/example_code/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
创建用于存储电影数据的表。
```
class Movies:
"""Encapsulates an Amazon DynamoDB table of movie data.
Example data structure for a movie record in this table:
{
"year": 1999,
"title": "For Love of the Game",
"info": {
"directors": ["Sam Raimi"],
"release_date": "1999-09-15T00:00:00Z",
"rating": 6.3,
"plot": "A washed up pitcher flashes through his career.",
"rank": 4987,
"running_time_secs": 8220,
"actors": [
"Kevin Costner",
"Kelly Preston",
"John C. Reilly"
]
}
}
"""
def __init__(self, dyn_resource):
"""
:param dyn_resource: A Boto3 DynamoDB resource.
"""
self.dyn_resource = dyn_resource
# The table variable is set during the scenario in the call to
# 'exists' if the table exists. Otherwise, it is set by 'create_table'.
self.table = None
def create_table(self, table_name):
"""
Creates an Amazon DynamoDB table that can be used to store movie data.
The table uses the release year of the movie as the partition key and the
title as the sort key.
:param table_name: The name of the table to create.
:return: The newly created table.
"""
try:
self.table = self.dyn_resource.create_table(
TableName=table_name,
KeySchema=[
{"AttributeName": "year", "KeyType": "HASH"}, # Partition key
{"AttributeName": "title", "KeyType": "RANGE"}, # Sort key
],
AttributeDefinitions=[
{"AttributeName": "year", "AttributeType": "N"},
{"AttributeName": "title", "AttributeType": "S"},
],
BillingMode='PAY_PER_REQUEST',
)
self.table.wait_until_exists()
except ClientError as err:
logger.error(
"Couldn't create table %s. Here's why: %s: %s",
table_name,
err.response["Error"]["Code"],
err.response["Error"]["Message"],
)
raise
else:
return self.table
```
+ 有关 API 详细信息，请参阅《AWS SDK for Python (Boto3) API Reference》**中的 [CreateTable](https://docs.aws.amazon.com/goto/boto3/dynamodb-2012-08-10/CreateTable)。
------
#### [ Ruby ]
**适用于 Ruby 的 SDK**
查看 GitHub，了解更多信息。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/ruby/example_code/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
```
# Encapsulates an Amazon DynamoDB table of movie data.
class Scaffold
attr_reader :dynamo_resource, :table_name, :table
def initialize(table_name)
client = Aws::DynamoDB::Client.new(region: 'us-east-1')
@dynamo_resource = Aws::DynamoDB::Resource.new(client: client)
@table_name = table_name
@table = nil
@logger = Logger.new($stdout)
@logger.level = Logger::DEBUG
end
# Creates an Amazon DynamoDB table that can be used to store movie data.
# The table uses the release year of the movie as the partition key and the
# title as the sort key.
#
# @param table_name [String] The name of the table to create.
# @return [Aws::DynamoDB::Table] The newly created table.
def create_table(table_name)
@table = @dynamo_resource.create_table(
table_name: table_name,
key_schema: [
{ attribute_name: 'year', key_type: 'HASH' }, # Partition key
{ attribute_name: 'title', key_type: 'RANGE' } # Sort key
],
attribute_definitions: [
{ attribute_name: 'year', attribute_type: 'N' },
{ attribute_name: 'title', attribute_type: 'S' }
],
billing_mode: 'PAY_PER_REQUEST'
)
@dynamo_resource.client.wait_until(:table_exists, table_name: table_name)
@table
rescue Aws::DynamoDB::Errors::ServiceError => e
@logger.error("Failed create table #{table_name}:\n#{e.code}: #{e.message}")
raise
end
```
+ 有关 API 详细信息，请参阅《适用于 Ruby 的 AWS SDK API Reference》**中的 [CreateTable](https://docs.aws.amazon.com/goto/SdkForRubyV3/dynamodb-2012-08-10/CreateTable)。
------
#### [ Rust ]
**适用于 Rust 的 SDK**
查看 GitHub，了解更多信息。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/rustv1/examples/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
```
pub async fn create_table(
client: &Client,
table: &str,
key: &str,
) -> Result {
let a_name: String = key.into();
let table_name: String = table.into();
let ad = AttributeDefinition::builder()
.attribute_name(&a_name)
.attribute_type(ScalarAttributeType::S)
.build()
.map_err(Error::BuildError)?;
let ks = KeySchemaElement::builder()
.attribute_name(&a_name)
.key_type(KeyType::Hash)
.build()
.map_err(Error::BuildError)?;
let create_table_response = client
.create_table()
.table_name(table_name)
.key_schema(ks)
.attribute_definitions(ad)
.billing_mode(BillingMode::PayPerRequest)
.send()
.await;
match create_table_response {
Ok(out) => {
println!("Added table {} with key {}", table, key);
Ok(out)
}
Err(e) => {
eprintln!("Got an error creating table:");
eprintln!("{}", e);
Err(Error::unhandled(e))
}
}
}
```
+ 有关 API 详细信息，请参阅《AWS SDK for Rust API Reference》**中的 [CreateTable](https://docs.rs/aws-sdk-dynamodb/latest/aws_sdk_dynamodb/client/struct.Client.html#method.create_table)。
------
#### [ SAP ABAP ]
**适用于 SAP ABAP 的 SDK**
查看 GitHub，了解更多信息。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/sap-abap/services/dyn#code-examples)中查找完整示例，了解如何进行设置和运行。
```
TRY.
DATA(lt_keyschema) = VALUE /aws1/cl_dynkeyschemaelement=>tt_keyschema(
( NEW /aws1/cl_dynkeyschemaelement( iv_attributename = 'year'
iv_keytype = 'HASH' ) )
( NEW /aws1/cl_dynkeyschemaelement( iv_attributename = 'title'
iv_keytype = 'RANGE' ) ) ).
DATA(lt_attributedefinitions) = VALUE /aws1/cl_dynattributedefn=>tt_attributedefinitions(
( NEW /aws1/cl_dynattributedefn( iv_attributename = 'year'
iv_attributetype = 'N' ) )
( NEW /aws1/cl_dynattributedefn( iv_attributename = 'title'
iv_attributetype = 'S' ) ) ).
" Adjust read/write capacities as desired.
DATA(lo_dynprovthroughput) = NEW /aws1/cl_dynprovthroughput(
iv_readcapacityunits = 5
iv_writecapacityunits = 5 ).
oo_result = lo_dyn->createtable(
it_keyschema = lt_keyschema
iv_tablename = iv_table_name
it_attributedefinitions = lt_attributedefinitions
io_provisionedthroughput = lo_dynprovthroughput ).
" Table creation can take some time. Wait till table exists before returning.
lo_dyn->get_waiter( )->tableexists(
iv_max_wait_time = 200
iv_tablename = iv_table_name ).
MESSAGE 'DynamoDB Table' && iv_table_name && 'created.' TYPE 'I'.
" This exception can happen if the table already exists.
CATCH /aws1/cx_dynresourceinuseex INTO DATA(lo_resourceinuseex).
DATA(lv_error) = |"{ lo_resourceinuseex->av_err_code }" - { lo_resourceinuseex->av_err_msg }|.
MESSAGE lv_error TYPE 'E'.
ENDTRY.
```
+ 有关 API 详细信息，请参阅《AWS SDK for SAP ABAP API Reference》**中的 [CreateTable](https://docs.aws.amazon.com/sdk-for-sap-abap/v1/api/latest/index.html)。
------
#### [ Swift ]
**适用于 Swift 的 SDK**
查看 GitHub，了解更多信息。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/swift/example_code/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
```
import AWSDynamoDB
///
/// Create a movie table in the Amazon DynamoDB data store.
///
private func createTable() async throws {
do {
guard let client = self.ddbClient else {
throw MoviesError.UninitializedClient
}
let input = CreateTableInput(
attributeDefinitions: [
DynamoDBClientTypes.AttributeDefinition(attributeName: "year", attributeType: .n),
DynamoDBClientTypes.AttributeDefinition(attributeName: "title", attributeType: .s)
],
billingMode: DynamoDBClientTypes.BillingMode.payPerRequest,
keySchema: [
DynamoDBClientTypes.KeySchemaElement(attributeName: "year", keyType: .hash),
DynamoDBClientTypes.KeySchemaElement(attributeName: "title", keyType: .range)
],
tableName: self.tableName
)
let output = try await client.createTable(input: input)
if output.tableDescription == nil {
throw MoviesError.TableNotFound
}
} catch {
print("ERROR: createTable:", dump(error))
throw error
}
}
```
+ 有关 API 详细信息，请参阅《AWS SDK for Swift API 参考》**中的 [CreateTable](https://sdk.amazonaws.com/swift/api/awsdynamodb/latest/documentation/awsdynamodb/dynamodbclient/createtable(input:))。
------
有关 AWS SDK 开发人员指南和代码示例的完整列表，请参阅 [结合使用 DynamoDB 与 AWS SDK](sdk-general-information-section.md) 本主题还包括有关入门的信息以及有关先前的 SDK 版本的详细信息。
# 将 `DeleteItem` 与 AWS SDK 或 CLI 配合使用
以下代码示例演示如何使用 `DeleteItem`。
操作示例是大型程序的代码摘录，必须在上下文中运行。您可以在以下代码示例中查看此操作的上下文：
+ [了解基本功能](example_dynamodb_Scenario_GettingStartedMovies_section.md)
+ [使用条件运算](example_dynamodb_Scenario_ConditionalOperations_section.md)
------
#### [ .NET ]
**适用于 .NET 的 SDK (v4)**
查看 GitHub，了解更多信息。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/dotnetv4/DynamoDB#code-examples) 中查找完整示例，了解如何进行设置和运行。
```
///
/// Deletes a single item from a DynamoDB table.
///
/// The name of the table from which the item
/// will be deleted.
/// A movie object containing the title and
/// year of the movie to delete.
/// A Boolean value indicating the success or failure of the
/// delete operation.
public async Task DeleteItemAsync(
string tableName,
Movie movieToDelete)
{
try
{
var key = new Dictionary
{
["title"] = new AttributeValue { S = movieToDelete.Title },
["year"] = new AttributeValue { N = movieToDelete.Year.ToString() },
};
var request = new DeleteItemRequest { TableName = tableName, Key = key, };
await _amazonDynamoDB.DeleteItemAsync(request);
return true;
}
catch (ResourceNotFoundException ex)
{
Console.WriteLine($"Table {tableName} was not found. {ex.Message}");
return false;
}
catch (AmazonDynamoDBException ex)
{
Console.WriteLine($"An Amazon DynamoDB error occurred while deleting item. {ex.Message}");
throw;
}
catch (Exception ex)
{
Console.WriteLine($"An error occurred while deleting item. {ex.Message}");
throw;
}
}
```
+ 有关 API 详细信息，请参阅《适用于 .NET 的 AWS SDK API Reference》**中的 [DeleteItem](https://docs.aws.amazon.com/goto/DotNetSDKV4/dynamodb-2012-08-10/DeleteItem)。
------
#### [ Bash ]
**AWS CLI 及 Bash 脚本**
查看 GitHub，了解更多信息。查找完整示例，了解如何在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/aws-cli/bash-linux/dynamodb#code-examples)中进行设置和运行。
```
##############################################################################
# function dynamodb_delete_item
#
# This function deletes an item from a DynamoDB table.
#
# Parameters:
# -n table_name -- The name of the table.
# -k keys -- Path to json file containing the keys that identify the item to delete.
#
# Returns:
# 0 - If successful.
# 1 - If it fails.
###########################################################################
function dynamodb_delete_item() {
local table_name keys response
local option OPTARG # Required to use getopts command in a function.
# ######################################
# Function usage explanation
#######################################
function usage() {
echo "function dynamodb_delete_item"
echo "Delete an item from a DynamoDB table."
echo " -n table_name -- The name of the table."
echo " -k keys -- Path to json file containing the keys that identify the item to delete."
echo ""
}
while getopts "n:k:h" option; do
case "${option}" in
n) table_name="${OPTARG}" ;;
k) keys="${OPTARG}" ;;
h)
usage
return 0
;;
\?)
echo "Invalid parameter"
usage
return 1
;;
esac
done
export OPTIND=1
if [[ -z "$table_name" ]]; then
errecho "ERROR: You must provide a table name with the -n parameter."
usage
return 1
fi
if [[ -z "$keys" ]]; then
errecho "ERROR: You must provide a keys json file path the -k parameter."
usage
return 1
fi
iecho "Parameters:\n"
iecho " table_name: $table_name"
iecho " keys: $keys"
iecho ""
response=$(aws dynamodb delete-item \
--table-name "$table_name" \
--key file://"$keys")
local error_code=${?}
if [[ $error_code -ne 0 ]]; then
aws_cli_error_log $error_code
errecho "ERROR: AWS reports delete-item operation failed.$response"
return 1
fi
return 0
}
```
本示例中使用的实用程序函数。
```
###############################################################################
# function iecho
#
# This function enables the script to display the specified text only if
# the global variable $VERBOSE is set to true.
###############################################################################
function iecho() {
if [[ $VERBOSE == true ]]; then
echo "$@"
fi
}
###############################################################################
# function errecho
#
# This function outputs everything sent to it to STDERR (standard error output).
###############################################################################
function errecho() {
printf "%s\n" "$*" 1>&2
}
##############################################################################
# function aws_cli_error_log()
#
# This function is used to log the error messages from the AWS CLI.
#
# See https://docs.aws.amazon.com/cli/latest/topic/return-codes.html#cli-aws-help-return-codes.
#
# The function expects the following argument:
# $1 - The error code returned by the AWS CLI.
#
# Returns:
# 0: - Success.
#
##############################################################################
function aws_cli_error_log() {
local err_code=$1
errecho "Error code : $err_code"
if [ "$err_code" == 1 ]; then
errecho " One or more S3 transfers failed."
elif [ "$err_code" == 2 ]; then
errecho " Command line failed to parse."
elif [ "$err_code" == 130 ]; then
errecho " Process received SIGINT."
elif [ "$err_code" == 252 ]; then
errecho " Command syntax invalid."
elif [ "$err_code" == 253 ]; then
errecho " The system environment or configuration was invalid."
elif [ "$err_code" == 254 ]; then
errecho " The service returned an error."
elif [ "$err_code" == 255 ]; then
errecho " 255 is a catch-all error."
fi
return 0
}
```
+ 有关 API 详细信息，请参阅《AWS CLI 命令参考》**中的 [DeleteItem](https://docs.aws.amazon.com/goto/aws-cli/dynamodb-2012-08-10/DeleteItem)。
------
#### [ C\$1\$1 ]
**SDK for C\$1\$1**
查看 GitHub，了解更多信息。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/cpp/example_code/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
```
//! Delete an item from an Amazon DynamoDB table.
/*!
\sa deleteItem()
\param tableName: The table name.
\param partitionKey: The partition key.
\param partitionValue: The value for the partition key.
\param clientConfiguration: AWS client configuration.
\return bool: Function succeeded.
*/
bool AwsDoc::DynamoDB::deleteItem(const Aws::String &tableName,
const Aws::String &partitionKey,
const Aws::String &partitionValue,
const Aws::Client::ClientConfiguration &clientConfiguration) {
Aws::DynamoDB::DynamoDBClient dynamoClient(clientConfiguration);
Aws::DynamoDB::Model::DeleteItemRequest request;
request.AddKey(partitionKey,
Aws::DynamoDB::Model::AttributeValue().SetS(partitionValue));
request.SetTableName(tableName);
const Aws::DynamoDB::Model::DeleteItemOutcome &outcome = dynamoClient.DeleteItem(
request);
if (outcome.IsSuccess()) {
std::cout << "Item \"" << partitionValue << "\" deleted!" << std::endl;
}
else {
std::cerr << "Failed to delete item: " << outcome.GetError().GetMessage()
<< std::endl;
return false;
}
return waitTableActive(tableName, dynamoClient);
}
```
等待表变为活动状态的代码。
```
//! Query a newly created DynamoDB table until it is active.
/*!
\sa waitTableActive()
\param waitTableActive: The DynamoDB table's name.
\param dynamoClient: A DynamoDB client.
\return bool: Function succeeded.
*/
bool AwsDoc::DynamoDB::waitTableActive(const Aws::String &tableName,
const Aws::DynamoDB::DynamoDBClient &dynamoClient) {
// Repeatedly call DescribeTable until table is ACTIVE.
const int MAX_QUERIES = 20;
Aws::DynamoDB::Model::DescribeTableRequest request;
request.SetTableName(tableName);
int count = 0;
while (count < MAX_QUERIES) {
const Aws::DynamoDB::Model::DescribeTableOutcome &result = dynamoClient.DescribeTable(
request);
if (result.IsSuccess()) {
Aws::DynamoDB::Model::TableStatus status = result.GetResult().GetTable().GetTableStatus();
if (Aws::DynamoDB::Model::TableStatus::ACTIVE != status) {
std::this_thread::sleep_for(std::chrono::seconds(1));
}
else {
return true;
}
}
else {
std::cerr << "Error DynamoDB::waitTableActive "
<< result.GetError().GetMessage() << std::endl;
return false;
}
count++;
}
return false;
}
```
+ 有关 API 详细信息，请参阅《适用于 C\$1\$1 的 AWS SDK API Reference》**中的 [DeleteItem](https://docs.aws.amazon.com/goto/SdkForCpp/dynamodb-2012-08-10/DeleteItem)。
------
#### [ CLI ]
**AWS CLI**
**示例 1：删除项**
以下 `delete-item` 示例从 `MusicCollection` 表中删除项，并请求有关已删除的项以及请求使用的容量的详细信息。
```
aws dynamodb delete-item \
--table-name MusicCollection \
--key file://key.json \
--return-values ALL_OLD \
--return-consumed-capacity TOTAL \
--return-item-collection-metrics SIZE
```
的内容`key.json`：
```
{
"Artist": {"S": "No One You Know"},
"SongTitle": {"S": "Scared of My Shadow"}
}
```
输出：
```
{
"Attributes": {
"AlbumTitle": {
"S": "Blue Sky Blues"
},
"Artist": {
"S": "No One You Know"
},
"SongTitle": {
"S": "Scared of My Shadow"
}
},
"ConsumedCapacity": {
"TableName": "MusicCollection",
"CapacityUnits": 2.0
},
"ItemCollectionMetrics": {
"ItemCollectionKey": {
"Artist": {
"S": "No One You Know"
}
},
"SizeEstimateRangeGB": [
0.0,
1.0
]
}
}
```
有关更多信息，请参阅《Amazon DynamoDB 开发人员指南》**中的[写入项](https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/WorkingWithItems.html#WorkingWithItems.WritingData)。
**示例 2：有条件地删除项**
以下示例仅在某项的 `ProductCategory` 为 `Sporting Goods` 或 `Gardening Supplies` 且其价格介于 500 和 600 之间时，才会将其从 `ProductCatalog` 表中删除。它会返回有关已删除项的详细信息。
```
aws dynamodb delete-item \
--table-name ProductCatalog \
--key '{"Id":{"N":"456"}}' \
--condition-expression "(ProductCategory IN (:cat1, :cat2)) and (#P between :lo and :hi)" \
--expression-attribute-names file://names.json \
--expression-attribute-values file://values.json \
--return-values ALL_OLD
```
的内容`names.json`：
```
{
"#P": "Price"
}
```
的内容`values.json`：
```
{
":cat1": {"S": "Sporting Goods"},
":cat2": {"S": "Gardening Supplies"},
":lo": {"N": "500"},
":hi": {"N": "600"}
}
```
输出：
```
{
"Attributes": {
"Id": {
"N": "456"
},
"Price": {
"N": "550"
},
"ProductCategory": {
"S": "Sporting Goods"
}
}
}
```
有关更多信息，请参阅《Amazon DynamoDB 开发人员指南》**中的[写入项](https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/WorkingWithItems.html#WorkingWithItems.WritingData)。
+ 有关 API 详细信息，请参阅《AWS CLI 命令参考》**中的 [DeleteItem](https://awscli.amazonaws.com/v2/documentation/api/latest/reference/dynamodb/delete-item.html)。
------
#### [ Go ]
**适用于 Go 的 SDK V2**
查看 GitHub，了解更多信息。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/gov2/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
```
import (
"context"
"errors"
"log"
"time"
"github.com/aws/aws-sdk-go-v2/aws"
"github.com/aws/aws-sdk-go-v2/feature/dynamodb/attributevalue"
"github.com/aws/aws-sdk-go-v2/feature/dynamodb/expression"
"github.com/aws/aws-sdk-go-v2/service/dynamodb"
"github.com/aws/aws-sdk-go-v2/service/dynamodb/types"
)
// TableBasics encapsulates the Amazon DynamoDB service actions used in the examples.
// It contains a DynamoDB service client that is used to act on the specified table.
type TableBasics struct {
DynamoDbClient *dynamodb.Client
TableName string
}
// DeleteMovie removes a movie from the DynamoDB table.
func (basics TableBasics) DeleteMovie(ctx context.Context, movie Movie) error {
_, err := basics.DynamoDbClient.DeleteItem(ctx, &dynamodb.DeleteItemInput{
TableName: aws.String(basics.TableName), Key: movie.GetKey(),
})
if err != nil {
log.Printf("Couldn't delete %v from the table. Here's why: %v\n", movie.Title, err)
}
return err
}
```
定义本示例中使用的 Movie 结构。
```
import (
"archive/zip"
"bytes"
"encoding/json"
"fmt"
"io"
"log"
"net/http"
"github.com/aws/aws-sdk-go-v2/feature/dynamodb/attributevalue"
"github.com/aws/aws-sdk-go-v2/service/dynamodb/types"
)
// Movie encapsulates data about a movie. Title and Year are the composite primary key
// of the movie in Amazon DynamoDB. Title is the sort key, Year is the partition key,
// and Info is additional data.
type Movie struct {
Title string `dynamodbav:"title"`
Year int `dynamodbav:"year"`
Info map[string]interface{} `dynamodbav:"info"`
}
// GetKey returns the composite primary key of the movie in a format that can be
// sent to DynamoDB.
func (movie Movie) GetKey() map[string]types.AttributeValue {
title, err := attributevalue.Marshal(movie.Title)
if err != nil {
panic(err)
}
year, err := attributevalue.Marshal(movie.Year)
if err != nil {
panic(err)
}
return map[string]types.AttributeValue{"title": title, "year": year}
}
// String returns the title, year, rating, and plot of a movie, formatted for the example.
func (movie Movie) String() string {
return fmt.Sprintf("%v\n\tReleased: %v\n\tRating: %v\n\tPlot: %v\n",
movie.Title, movie.Year, movie.Info["rating"], movie.Info["plot"])
}
```
+ 有关 API 详细信息，请参阅《适用于 Go 的 AWS SDK API Reference》**中的 [DeleteItem](https://pkg.go.dev/github.com/aws/aws-sdk-go-v2/service/dynamodb#Client.DeleteItem)。
------
#### [ Java ]
**适用于 Java 的 SDK 2.x**
查看 GitHub，了解更多信息。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javav2/example_code/dynamodb#code-examples) 中查找完整示例，了解如何进行设置和运行。
```
import software.amazon.awssdk.regions.Region;
import software.amazon.awssdk.services.dynamodb.DynamoDbClient;
import software.amazon.awssdk.services.dynamodb.model.AttributeValue;
import software.amazon.awssdk.services.dynamodb.model.DeleteItemRequest;
import software.amazon.awssdk.services.dynamodb.model.DynamoDbException;
import java.util.HashMap;
/**
* Before running this Java V2 code example, set up your development
* environment, including your credentials.
*
* For more information, see the following documentation topic:
*
* https://docs.aws.amazon.com/sdk-for-java/latest/developer-guide/get-started.html
*/
public class DeleteItem {
public static void main(String[] args) {
final String usage = """
Usage:
Where:
tableName - The Amazon DynamoDB table to delete the item from (for example, Music3).
key - The key used in the Amazon DynamoDB table (for example, Artist).\s
keyval - The key value that represents the item to delete (for example, Famous Band).
""";
if (args.length != 3) {
System.out.println(usage);
System.exit(1);
}
String tableName = args[0];
String key = args[1];
String keyVal = args[2];
System.out.format("Deleting item \"%s\" from %s\n", keyVal, tableName);
Region region = Region.US_EAST_1;
DynamoDbClient ddb = DynamoDbClient.builder()
.region(region)
.build();
deleteDynamoDBItem(ddb, tableName, key, keyVal);
ddb.close();
}
public static void deleteDynamoDBItem(DynamoDbClient ddb, String tableName, String key, String keyVal) {
HashMap keyToGet = new HashMap<>();
keyToGet.put(key, AttributeValue.builder()
.s(keyVal)
.build());
DeleteItemRequest deleteReq = DeleteItemRequest.builder()
.tableName(tableName)
.key(keyToGet)
.build();
try {
ddb.deleteItem(deleteReq);
} catch (DynamoDbException e) {
System.err.println(e.getMessage());
System.exit(1);
}
}
}
```
+ 有关 API 详细信息，请参阅《AWS SDK for Java 2.x API Reference》**中的 [DeleteItem](https://docs.aws.amazon.com/goto/SdkForJavaV2/dynamodb-2012-08-10/DeleteItem)。
------
#### [ JavaScript ]
**SDK for JavaScript (v3)**
查看 GitHub，了解更多信息。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javascriptv3/example_code/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
此示例使用文档客户端来简化在 DynamoDB 中处理项目的过程。有关 API 详细信息，请参阅 [DeleteCommand](https://docs.aws.amazon.com/AWSJavaScriptSDK/v3/latest/Package/-aws-sdk-lib-dynamodb/Class/DeleteCommand/)。
```
import { DynamoDBClient } from "@aws-sdk/client-dynamodb";
import { DynamoDBDocumentClient, DeleteCommand } from "@aws-sdk/lib-dynamodb";
const client = new DynamoDBClient({});
const docClient = DynamoDBDocumentClient.from(client);
export const main = async () => {
const command = new DeleteCommand({
TableName: "Sodas",
Key: {
Flavor: "Cola",
},
});
const response = await docClient.send(command);
console.log(response);
return response;
};
```
+ 有关更多信息，请参阅《适用于 JavaScript 的 AWS SDK 开发人员指南》[https://docs.aws.amazon.com/sdk-for-javascript/v3/developer-guide/dynamodb-example-table-read-write.html#dynamodb-example-table-read-write-deleting-an-item](https://docs.aws.amazon.com/sdk-for-javascript/v3/developer-guide/dynamodb-example-table-read-write.html#dynamodb-example-table-read-write-deleting-an-item)。
+ 有关 API 详细信息，请参阅《适用于 JavaScript 的 AWS SDK API Reference》**中的 [DeleteItem](https://docs.aws.amazon.com/AWSJavaScriptSDK/v3/latest/client/dynamodb/command/DeleteItemCommand)。
**SDK for JavaScript (v2)**
查看 GitHub，了解更多信息。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javascript/example_code/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
从表中删除项目。
```
// Load the AWS SDK for Node.js
var AWS = require("aws-sdk");
// Set the region
AWS.config.update({ region: "REGION" });
// Create the DynamoDB service object
var ddb = new AWS.DynamoDB({ apiVersion: "2012-08-10" });
var params = {
TableName: "TABLE",
Key: {
KEY_NAME: { N: "VALUE" },
},
};
// Call DynamoDB to delete the item from the table
ddb.deleteItem(params, function (err, data) {
if (err) {
console.log("Error", err);
} else {
console.log("Success", data);
}
});
```
使用 DynamoDB 文档客户端从表中删除项目。
```
// Load the AWS SDK for Node.js
var AWS = require("aws-sdk");
// Set the region
AWS.config.update({ region: "REGION" });
// Create DynamoDB document client
var docClient = new AWS.DynamoDB.DocumentClient({ apiVersion: "2012-08-10" });
var params = {
Key: {
HASH_KEY: VALUE,
},
TableName: "TABLE",
};
docClient.delete(params, function (err, data) {
if (err) {
console.log("Error", err);
} else {
console.log("Success", data);
}
});
```
+ 有关更多信息，请参阅《适用于 JavaScript 的 AWS SDK 开发人员指南》[https://docs.aws.amazon.com/sdk-for-javascript/v2/developer-guide/dynamodb-example-table-read-write.html#dynamodb-example-table-read-write-deleting-an-item](https://docs.aws.amazon.com/sdk-for-javascript/v2/developer-guide/dynamodb-example-table-read-write.html#dynamodb-example-table-read-write-deleting-an-item)。
+ 有关 API 详细信息，请参阅《适用于 JavaScript 的 AWS SDK API Reference》**中的 [DeleteItem](https://docs.aws.amazon.com/goto/AWSJavaScriptSDK/dynamodb-2012-08-10/DeleteItem)。
------
#### [ Kotlin ]
**SDK for Kotlin**
查看 GitHub，了解更多信息。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/kotlin/services/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
```
suspend fun deleteDynamoDBItem(
tableNameVal: String,
keyName: String,
keyVal: String,
) {
val keyToGet = mutableMapOf()
keyToGet[keyName] = AttributeValue.S(keyVal)
val request =
DeleteItemRequest {
tableName = tableNameVal
key = keyToGet
}
DynamoDbClient.fromEnvironment { region = "us-east-1" }.use { ddb ->
ddb.deleteItem(request)
println("Item with key matching $keyVal was deleted")
}
}
```
+ 有关 API 详细信息，请参阅《AWS SDK for Kotlin API Reference》**中的 [DeleteItem](https://sdk.amazonaws.com/kotlin/api/latest/index.html)。
------
#### [ PHP ]
**适用于 PHP 的 SDK**
查看 GitHub，了解更多信息。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/php/example_code/dynamodb#code-examples) 中查找完整示例，了解如何进行设置和运行。
```
$key = [
'Item' => [
'title' => [
'S' => $movieName,
],
'year' => [
'N' => $movieYear,
],
]
];
$service->deleteItemByKey($tableName, $key);
echo "But, bad news, this was a trap. That movie has now been deleted because of your rating...harsh.\n";
public function deleteItemByKey(string $tableName, array $key)
{
$this->dynamoDbClient->deleteItem([
'Key' => $key['Item'],
'TableName' => $tableName,
]);
}
```
+ 有关 API 详细信息，请参阅《适用于 PHP 的 AWS SDK API Reference》**中的 [DeleteItem](https://docs.aws.amazon.com/goto/SdkForPHPV3/dynamodb-2012-08-10/DeleteItem)。
------
#### [ PowerShell ]
**适用于 PowerShell V4 的工具**
**示例 1：移除与提供的键匹配的 DynamoDB 项目。**
```
$key = @{
SongTitle = 'Somewhere Down The Road'
Artist = 'No One You Know'
} | ConvertTo-DDBItem
Remove-DDBItem -TableName 'Music' -Key $key -Confirm:$false
```
+ 有关 API 详细信息，请参阅《AWS Tools for PowerShell Cmdlet Reference (V4)》**中的 [DeleteItem](https://docs.aws.amazon.com/powershell/v4/reference)。
**适用于 PowerShell V5 的工具**
**示例 1：移除与提供的键匹配的 DynamoDB 项目。**
```
$key = @{
SongTitle = 'Somewhere Down The Road'
Artist = 'No One You Know'
} | ConvertTo-DDBItem
Remove-DDBItem -TableName 'Music' -Key $key -Confirm:$false
```
+ 有关 API 详细信息，请参阅《AWS Tools for PowerShell Cmdlet Reference (V5)》**中的 [DeleteItem](https://docs.aws.amazon.com/powershell/v5/reference)。
------
#### [ Python ]
**适用于 Python 的 SDK（Boto3）**
查看 GitHub，了解更多信息。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/python/example_code/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
```
class Movies:
"""Encapsulates an Amazon DynamoDB table of movie data.
Example data structure for a movie record in this table:
{
"year": 1999,
"title": "For Love of the Game",
"info": {
"directors": ["Sam Raimi"],
"release_date": "1999-09-15T00:00:00Z",
"rating": 6.3,
"plot": "A washed up pitcher flashes through his career.",
"rank": 4987,
"running_time_secs": 8220,
"actors": [
"Kevin Costner",
"Kelly Preston",
"John C. Reilly"
]
}
}
"""
def __init__(self, dyn_resource):
"""
:param dyn_resource: A Boto3 DynamoDB resource.
"""
self.dyn_resource = dyn_resource
# The table variable is set during the scenario in the call to
# 'exists' if the table exists. Otherwise, it is set by 'create_table'.
self.table = None
def delete_movie(self, title, year):
"""
Deletes a movie from the table.
:param title: The title of the movie to delete.
:param year: The release year of the movie to delete.
"""
try:
self.table.delete_item(Key={"year": year, "title": title})
except ClientError as err:
logger.error(
"Couldn't delete movie %s. Here's why: %s: %s",
title,
err.response["Error"]["Code"],
err.response["Error"]["Message"],
)
raise
```
您可以指定条件，以便只有在项目满足特定条件时才会被删除。
```
class UpdateQueryWrapper:
def __init__(self, table):
self.table = table
def delete_underrated_movie(self, title, year, rating):
"""
Deletes a movie only if it is rated below a specified value. By using a
condition expression in a delete operation, you can specify that an item is
deleted only when it meets certain criteria.
:param title: The title of the movie to delete.
:param year: The release year of the movie to delete.
:param rating: The rating threshold to check before deleting the movie.
"""
try:
self.table.delete_item(
Key={"year": year, "title": title},
ConditionExpression="info.rating <= :val",
ExpressionAttributeValues={":val": Decimal(str(rating))},
)
except ClientError as err:
if err.response["Error"]["Code"] == "ConditionalCheckFailedException":
logger.warning(
"Didn't delete %s because its rating is greater than %s.",
title,
rating,
)
else:
logger.error(
"Couldn't delete movie %s. Here's why: %s: %s",
title,
err.response["Error"]["Code"],
err.response["Error"]["Message"],
)
raise
```
+ 有关 API 详细信息，请参阅《AWS SDK for Python (Boto3) API Reference》**中的 [DeleteItem](https://docs.aws.amazon.com/goto/boto3/dynamodb-2012-08-10/DeleteItem)。
------
#### [ Ruby ]
**适用于 Ruby 的 SDK**
查看 GitHub，了解更多信息。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/ruby/example_code/dynamodb#code-examples) 中查找完整示例，了解如何进行设置和运行。
```
class DynamoDBBasics
attr_reader :dynamo_resource, :table
def initialize(table_name)
client = Aws::DynamoDB::Client.new(region: 'us-east-1')
@dynamo_resource = Aws::DynamoDB::Resource.new(client: client)
@table = @dynamo_resource.table(table_name)
end
# Deletes a movie from the table.
#
# @param title [String] The title of the movie to delete.
# @param year [Integer] The release year of the movie to delete.
def delete_item(title, year)
@table.delete_item(key: { 'year' => year, 'title' => title })
rescue Aws::DynamoDB::Errors::ServiceError => e
puts("Couldn't delete movie #{title}. Here's why:")
puts("\t#{e.code}: #{e.message}")
raise
end
```
+ 有关 API 详细信息，请参阅《适用于 Ruby 的 AWS SDK API Reference》**中的 [DeleteItem](https://docs.aws.amazon.com/goto/SdkForRubyV3/dynamodb-2012-08-10/DeleteItem)。
------
#### [ Rust ]
**适用于 Rust 的 SDK**
查看 GitHub，了解更多信息。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/rustv1/examples/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
```
pub async fn delete_item(
client: &Client,
table: &str,
key: &str,
value: &str,
) -> Result {
match client
.delete_item()
.table_name(table)
.key(key, AttributeValue::S(value.into()))
.send()
.await
{
Ok(out) => {
println!("Deleted item from table");
Ok(out)
}
Err(e) => Err(Error::unhandled(e)),
}
}
```
+ 有关 API 详细信息，请参阅《AWS SDK for Rust API Reference》**中的 [DeleteItem](https://docs.rs/aws-sdk-dynamodb/latest/aws_sdk_dynamodb/client/struct.Client.html#method.delete_item)。
------
#### [ SAP ABAP ]
**适用于 SAP ABAP 的 SDK**
查看 GitHub，了解更多信息。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/sap-abap/services/dyn#code-examples)中查找完整示例，了解如何进行设置和运行。
```
TRY.
DATA(lo_resp) = lo_dyn->deleteitem(
iv_tablename = iv_table_name
it_key = it_key_input ).
MESSAGE 'Deleted one item.' TYPE 'I'.
CATCH /aws1/cx_dyncondalcheckfaile00.
MESSAGE 'A condition specified in the operation could not be evaluated.' TYPE 'E'.
CATCH /aws1/cx_dynresourcenotfoundex.
MESSAGE 'The table or index does not exist' TYPE 'E'.
CATCH /aws1/cx_dyntransactconflictex.
MESSAGE 'Another transaction is using the item' TYPE 'E'.
ENDTRY.
```
+ 有关 API 详细信息，请参阅《AWS SDK for SAP ABAP API Reference》**中的 [DeleteItem](https://docs.aws.amazon.com/sdk-for-sap-abap/v1/api/latest/index.html)。
------
#### [ Swift ]
**适用于 Swift 的 SDK**
查看 GitHub，了解更多信息。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/swift/example_code/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
```
import AWSDynamoDB
/// Delete a movie, given its title and release year.
///
/// - Parameters:
/// - title: The movie's title.
/// - year: The movie's release year.
///
func delete(title: String, year: Int) async throws {
do {
guard let client = self.ddbClient else {
throw MoviesError.UninitializedClient
}
let input = DeleteItemInput(
key: [
"year": .n(String(year)),
"title": .s(title)
],
tableName: self.tableName
)
_ = try await client.deleteItem(input: input)
} catch {
print("ERROR: delete:", dump(error))
throw error
}
}
```
+ 有关 API 详细信息，请参阅《AWS SDK for Swift API 参考》**中的 [DeleteItem](https://sdk.amazonaws.com/swift/api/awsdynamodb/latest/documentation/awsdynamodb/dynamodbclient/deleteitem(input:))。
------
有关 AWS SDK 开发人员指南和代码示例的完整列表，请参阅 [结合使用 DynamoDB 与 AWS SDK](sdk-general-information-section.md) 本主题还包括有关入门的信息以及有关先前的 SDK 版本的详细信息。
# 将 `DeleteTable` 与 AWS SDK 或 CLI 配合使用
以下代码示例演示如何使用 `DeleteTable`。
操作示例是大型程序的代码摘录，必须在上下文中运行。您可以在以下代码示例中查看此操作的上下文：
+ [了解基本功能](example_dynamodb_Scenario_GettingStartedMovies_section.md)
+ [借助 DAX 加快读取速度](example_dynamodb_Usage_DaxDemo_section.md)
+ [创建和管理 MRSC 全局表](example_dynamodb_Scenario_MRSCGlobalTables_section.md)
+ [管理全局二级索引](example_dynamodb_Scenario_GSILifecycle_section.md)
+ [使用全局表和多区域复制最终一致性（MREC）](example_dynamodb_Scenario_MultiRegionReplication_section.md)
------
#### [ .NET ]
**适用于 .NET 的 SDK (v4)**
查看 GitHub，了解更多信息。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/dotnetv4/DynamoDB#code-examples) 中查找完整示例，了解如何进行设置和运行。
```
///
/// Deletes a DynamoDB table.
///
/// The name of the table to delete.
/// A Boolean value indicating the success of the operation.
public async Task DeleteTableAsync(string tableName)
{
try
{
var request = new DeleteTableRequest
{
TableName = tableName,
};
var response = await _amazonDynamoDB.DeleteTableAsync(request);
Console.WriteLine($"Table {response.TableDescription.TableName} successfully deleted.");
return true;
}
catch (ResourceNotFoundException ex)
{
Console.WriteLine($"Table {tableName} was not found and cannot be deleted. {ex.Message}");
return false;
}
catch (AmazonDynamoDBException ex)
{
Console.WriteLine($"An Amazon DynamoDB error occurred while deleting table {tableName}. {ex.Message}");
return false;
}
catch (Exception ex)
{
Console.WriteLine($"An error occurred while deleting table {tableName}. {ex.Message}");
return false;
}
}
```
+ 有关 API 详细信息，请参阅《适用于 .NET 的 AWS SDK API Reference》**中的 [DeleteTable](https://docs.aws.amazon.com/goto/DotNetSDKV4/dynamodb-2012-08-10/DeleteTable)。
------
#### [ Bash ]
**AWS CLI 及 Bash 脚本**
查看 GitHub，了解更多信息。查找完整示例，了解如何在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/aws-cli/bash-linux/dynamodb#code-examples)中进行设置和运行。
```
###############################################################################
# function dynamodb_delete_table
#
# This function deletes a DynamoDB table.
#
# Parameters:
# -n table_name -- The name of the table to delete.
#
# Returns:
# 0 - If successful.
# 1 - If it fails.
###############################################################################
function dynamodb_delete_table() {
local table_name response
local option OPTARG # Required to use getopts command in a function.
# bashsupport disable=BP5008
function usage() {
echo "function dynamodb_delete_table"
echo "Deletes an Amazon DynamoDB table."
echo " -n table_name -- The name of the table to delete."
echo ""
}
# Retrieve the calling parameters.
while getopts "n:h" option; do
case "${option}" in
n) table_name="${OPTARG}" ;;
h)
usage
return 0
;;
\?)
echo "Invalid parameter"
usage
return 1
;;
esac
done
export OPTIND=1
if [[ -z "$table_name" ]]; then
errecho "ERROR: You must provide a table name with the -n parameter."
usage
return 1
fi
iecho "Parameters:\n"
iecho " table_name: $table_name"
iecho ""
response=$(aws dynamodb delete-table \
--table-name "$table_name")
local error_code=${?}
if [[ $error_code -ne 0 ]]; then
aws_cli_error_log $error_code
errecho "ERROR: AWS reports delete-table operation failed.$response"
return 1
fi
return 0
}
```
本示例中使用的实用程序函数。
```
###############################################################################
# function iecho
#
# This function enables the script to display the specified text only if
# the global variable $VERBOSE is set to true.
###############################################################################
function iecho() {
if [[ $VERBOSE == true ]]; then
echo "$@"
fi
}
###############################################################################
# function errecho
#
# This function outputs everything sent to it to STDERR (standard error output).
###############################################################################
function errecho() {
printf "%s\n" "$*" 1>&2
}
##############################################################################
# function aws_cli_error_log()
#
# This function is used to log the error messages from the AWS CLI.
#
# See https://docs.aws.amazon.com/cli/latest/topic/return-codes.html#cli-aws-help-return-codes.
#
# The function expects the following argument:
# $1 - The error code returned by the AWS CLI.
#
# Returns:
# 0: - Success.
#
##############################################################################
function aws_cli_error_log() {
local err_code=$1
errecho "Error code : $err_code"
if [ "$err_code" == 1 ]; then
errecho " One or more S3 transfers failed."
elif [ "$err_code" == 2 ]; then
errecho " Command line failed to parse."
elif [ "$err_code" == 130 ]; then
errecho " Process received SIGINT."
elif [ "$err_code" == 252 ]; then
errecho " Command syntax invalid."
elif [ "$err_code" == 253 ]; then
errecho " The system environment or configuration was invalid."
elif [ "$err_code" == 254 ]; then
errecho " The service returned an error."
elif [ "$err_code" == 255 ]; then
errecho " 255 is a catch-all error."
fi
return 0
}
```
+ 有关 API 详细信息，请参阅《AWS CLI 命令参考》**中的 [DeleteTable](https://docs.aws.amazon.com/goto/aws-cli/dynamodb-2012-08-10/DeleteTable)。
------
#### [ C\$1\$1 ]
**SDK for C\$1\$1**
查看 GitHub，了解更多信息。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/cpp/example_code/dynamodb#code-examples) 中查找完整示例，了解如何进行设置和运行。
```
//! Delete an Amazon DynamoDB table.
/*!
\sa deleteTable()
\param tableName: The DynamoDB table name.
\param clientConfiguration: AWS client configuration.
\return bool: Function succeeded.
*/
bool AwsDoc::DynamoDB::deleteTable(const Aws::String &tableName,
const Aws::Client::ClientConfiguration &clientConfiguration) {
Aws::DynamoDB::DynamoDBClient dynamoClient(clientConfiguration);
Aws::DynamoDB::Model::DeleteTableRequest request;
request.SetTableName(tableName);
const Aws::DynamoDB::Model::DeleteTableOutcome &result = dynamoClient.DeleteTable(
request);
if (result.IsSuccess()) {
std::cout << "Your table \""
<< result.GetResult().GetTableDescription().GetTableName()
<< " was deleted.\n";
}
else {
std::cerr << "Failed to delete table: " << result.GetError().GetMessage()
<< std::endl;
}
return result.IsSuccess();
}
```
+ 有关 API 详细信息，请参阅《适用于 C\$1\$1 的 AWS SDK API Reference》**中的 [DeleteTable](https://docs.aws.amazon.com/goto/SdkForCpp/dynamodb-2012-08-10/DeleteTable)。
------
#### [ CLI ]
**AWS CLI**
**删除表**
以下 `delete-table` 示例将删除 `MusicCollection` 表。
```
aws dynamodb delete-table \
--table-name MusicCollection
```
输出：
```
{
"TableDescription": {
"TableStatus": "DELETING",
"TableSizeBytes": 0,
"ItemCount": 0,
"TableName": "MusicCollection",
"ProvisionedThroughput": {
"NumberOfDecreasesToday": 0,
"WriteCapacityUnits": 5,
"ReadCapacityUnits": 5
}
}
}
```
有关更多信息，请参阅《Amazon DynamoDB 开发人员指南》**中的[删除表](https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/WorkingWithTables.Basics.html#WorkingWithTables.Basics.DeleteTable)。
+ 有关 API 详细信息，请参阅《AWS CLI 命令参考》**中的 [DeleteTable](https://awscli.amazonaws.com/v2/documentation/api/latest/reference/dynamodb/delete-table.html)。
------
#### [ Go ]
**适用于 Go 的 SDK V2**
查看 GitHub，了解更多信息。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/gov2/dynamodb#code-examples) 中查找完整示例，了解如何进行设置和运行。
```
import (
"context"
"errors"
"log"
"time"
"github.com/aws/aws-sdk-go-v2/aws"
"github.com/aws/aws-sdk-go-v2/feature/dynamodb/attributevalue"
"github.com/aws/aws-sdk-go-v2/feature/dynamodb/expression"
"github.com/aws/aws-sdk-go-v2/service/dynamodb"
"github.com/aws/aws-sdk-go-v2/service/dynamodb/types"
)
// TableBasics encapsulates the Amazon DynamoDB service actions used in the examples.
// It contains a DynamoDB service client that is used to act on the specified table.
type TableBasics struct {
DynamoDbClient *dynamodb.Client
TableName string
}
// DeleteTable deletes the DynamoDB table and all of its data.
func (basics TableBasics) DeleteTable(ctx context.Context) error {
_, err := basics.DynamoDbClient.DeleteTable(ctx, &dynamodb.DeleteTableInput{
TableName: aws.String(basics.TableName)})
if err != nil {
log.Printf("Couldn't delete table %v. Here's why: %v\n", basics.TableName, err)
}
return err
}
```
+ 有关 API 详细信息，请参阅《适用于 Go 的 AWS SDK API Reference》**中的 [DeleteTable](https://pkg.go.dev/github.com/aws/aws-sdk-go-v2/service/dynamodb#Client.DeleteTable)。
------
#### [ Java ]
**适用于 Java 的 SDK 2.x**
查看 GitHub，了解更多信息。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javav2/example_code/dynamodb#code-examples) 中查找完整示例，了解如何进行设置和运行。
```
import software.amazon.awssdk.regions.Region;
import software.amazon.awssdk.services.dynamodb.model.DynamoDbException;
import software.amazon.awssdk.services.dynamodb.DynamoDbClient;
import software.amazon.awssdk.services.dynamodb.model.DeleteTableRequest;
/**
* Before running this Java V2 code example, set up your development
* environment, including your credentials.
*
* For more information, see the following documentation topic:
*
* https://docs.aws.amazon.com/sdk-for-java/latest/developer-guide/get-started.html
*/
public class DeleteTable {
public static void main(String[] args) {
final String usage = """
Usage:
Where:
tableName - The Amazon DynamoDB table to delete (for example, Music3).
**Warning** This program will delete the table that you specify!
""";
if (args.length != 1) {
System.out.println(usage);
System.exit(1);
}
String tableName = args[0];
System.out.format("Deleting the Amazon DynamoDB table %s...\n", tableName);
Region region = Region.US_EAST_1;
DynamoDbClient ddb = DynamoDbClient.builder()
.region(region)
.build();
deleteDynamoDBTable(ddb, tableName);
ddb.close();
}
public static void deleteDynamoDBTable(DynamoDbClient ddb, String tableName) {
DeleteTableRequest request = DeleteTableRequest.builder()
.tableName(tableName)
.build();
try {
ddb.deleteTable(request);
} catch (DynamoDbException e) {
System.err.println(e.getMessage());
System.exit(1);
}
System.out.println(tableName + " was successfully deleted!");
}
}
```
+ 有关 API 详细信息，请参阅《AWS SDK for Java 2.x API Reference》**中的 [DeleteTable](https://docs.aws.amazon.com/goto/SdkForJavaV2/dynamodb-2012-08-10/DeleteTable)。
------
#### [ JavaScript ]
**SDK for JavaScript (v3)**
查看 GitHub，了解更多信息。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javascriptv3/example_code/dynamodb#code-examples) 中查找完整示例，了解如何进行设置和运行。
```
import { DeleteTableCommand, DynamoDBClient } from "@aws-sdk/client-dynamodb";
const client = new DynamoDBClient({});
export const main = async () => {
const command = new DeleteTableCommand({
TableName: "DecafCoffees",
});
const response = await client.send(command);
console.log(response);
return response;
};
```
+ 有关 API 详细信息，请参阅《适用于 JavaScript 的 AWS SDK API Reference》**中的 [DeleteTable](https://docs.aws.amazon.com/AWSJavaScriptSDK/v3/latest/client/dynamodb/command/DeleteTableCommand)。
**SDK for JavaScript (v2)**
查看 GitHub，了解更多信息。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javascript/example_code/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
```
// Load the AWS SDK for Node.js
var AWS = require("aws-sdk");
// Set the region
AWS.config.update({ region: "REGION" });
// Create the DynamoDB service object
var ddb = new AWS.DynamoDB({ apiVersion: "2012-08-10" });
var params = {
TableName: process.argv[2],
};
// Call DynamoDB to delete the specified table
ddb.deleteTable(params, function (err, data) {
if (err && err.code === "ResourceNotFoundException") {
console.log("Error: Table not found");
} else if (err && err.code === "ResourceInUseException") {
console.log("Error: Table in use");
} else {
console.log("Success", data);
}
});
```
+ 有关更多信息，请参阅《适用于 JavaScript 的 AWS SDK 开发人员指南》[https://docs.aws.amazon.com/sdk-for-javascript/v2/developer-guide/dynamodb-examples-using-tables.html#dynamodb-examples-using-tables-deleting-a-table](https://docs.aws.amazon.com/sdk-for-javascript/v2/developer-guide/dynamodb-examples-using-tables.html#dynamodb-examples-using-tables-deleting-a-table)。
+ 有关 API 详细信息，请参阅《适用于 JavaScript 的 AWS SDK API Reference》**中的 [DeleteTable](https://docs.aws.amazon.com/goto/AWSJavaScriptSDK/dynamodb-2012-08-10/DeleteTable)。
------
#### [ Kotlin ]
**SDK for Kotlin**
查看 GitHub，了解更多信息。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/kotlin/services/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
```
suspend fun deleteDynamoDBTable(tableNameVal: String) {
val request =
DeleteTableRequest {
tableName = tableNameVal
}
DynamoDbClient.fromEnvironment { region = "us-east-1" }.use { ddb ->
ddb.deleteTable(request)
println("$tableNameVal was deleted")
}
}
```
+ 有关 API 详细信息，请参阅《AWS SDK for Kotlin API Reference》**中的 [DeleteTable](https://sdk.amazonaws.com/kotlin/api/latest/index.html)。
------
#### [ PHP ]
**适用于 PHP 的 SDK**
查看 GitHub，了解更多信息。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/php/example_code/dynamodb#code-examples) 中查找完整示例，了解如何进行设置和运行。
```
public function deleteTable(string $TableName)
{
$this->customWaiter(function () use ($TableName) {
return $this->dynamoDbClient->deleteTable([
'TableName' => $TableName,
]);
});
}
```
+ 有关 API 详细信息，请参阅《适用于 PHP 的 AWS SDK API Reference》**中的 [DeleteTable](https://docs.aws.amazon.com/goto/SdkForPHPV3/dynamodb-2012-08-10/DeleteTable)。
------
#### [ PowerShell ]
**适用于 PowerShell V4 的工具**
**示例 1：删除指定的表。在操作继续之前，系统会提示您进行确认。**
```
Remove-DDBTable -TableName "myTable"
```
**示例 2：删除指定的表。在操作继续之前，系统不会提示您进行确认。**
```
Remove-DDBTable -TableName "myTable" -Force
```
+ 有关 API 详细信息，请参阅《AWS Tools for PowerShell Cmdlet Reference (V4)》**中的 [DeleteTable](https://docs.aws.amazon.com/powershell/v4/reference)。
**适用于 PowerShell V5 的工具**
**示例 1：删除指定的表。在操作继续之前，系统会提示您进行确认。**
```
Remove-DDBTable -TableName "myTable"
```
**示例 2：删除指定的表。在操作继续之前，系统不会提示您进行确认。**
```
Remove-DDBTable -TableName "myTable" -Force
```
+ 有关 API 详细信息，请参阅《AWS Tools for PowerShell Cmdlet Reference (V5)》**中的 [DeleteTable](https://docs.aws.amazon.com/powershell/v5/reference)。
------
#### [ Python ]
**适用于 Python 的 SDK（Boto3）**
查看 GitHub，了解更多信息。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/python/example_code/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
```
class Movies:
"""Encapsulates an Amazon DynamoDB table of movie data.
Example data structure for a movie record in this table:
{
"year": 1999,
"title": "For Love of the Game",
"info": {
"directors": ["Sam Raimi"],
"release_date": "1999-09-15T00:00:00Z",
"rating": 6.3,
"plot": "A washed up pitcher flashes through his career.",
"rank": 4987,
"running_time_secs": 8220,
"actors": [
"Kevin Costner",
"Kelly Preston",
"John C. Reilly"
]
}
}
"""
def __init__(self, dyn_resource):
"""
:param dyn_resource: A Boto3 DynamoDB resource.
"""
self.dyn_resource = dyn_resource
# The table variable is set during the scenario in the call to
# 'exists' if the table exists. Otherwise, it is set by 'create_table'.
self.table = None
def delete_table(self):
"""
Deletes the table.
"""
try:
self.table.delete()
self.table = None
except ClientError as err:
logger.error(
"Couldn't delete table. Here's why: %s: %s",
err.response["Error"]["Code"],
err.response["Error"]["Message"],
)
raise
```
+ 有关 API 详细信息，请参阅《AWS SDK for Python (Boto3) API Reference》**中的 [DeleteTable](https://docs.aws.amazon.com/goto/boto3/dynamodb-2012-08-10/DeleteTable)。
------
#### [ Ruby ]
**适用于 Ruby 的 SDK**
查看 GitHub，了解更多信息。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/ruby/example_code/dynamodb#code-examples) 中查找完整示例，了解如何进行设置和运行。
```
# Encapsulates an Amazon DynamoDB table of movie data.
class Scaffold
attr_reader :dynamo_resource, :table_name, :table
def initialize(table_name)
client = Aws::DynamoDB::Client.new(region: 'us-east-1')
@dynamo_resource = Aws::DynamoDB::Resource.new(client: client)
@table_name = table_name
@table = nil
@logger = Logger.new($stdout)
@logger.level = Logger::DEBUG
end
# Deletes the table.
def delete_table
@table.delete
@table = nil
rescue Aws::DynamoDB::Errors::ServiceError => e
puts("Couldn't delete table. Here's why:")
puts("\t#{e.code}: #{e.message}")
raise
end
```
+ 有关 API 详细信息，请参阅《适用于 Ruby 的 AWS SDK API Reference》**中的 [DeleteTable](https://docs.aws.amazon.com/goto/SdkForRubyV3/dynamodb-2012-08-10/DeleteTable)。
------
#### [ Rust ]
**适用于 Rust 的 SDK**
查看 GitHub，了解更多信息。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/rustv1/examples/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
```
pub async fn delete_table(client: &Client, table: &str) -> Result {
let resp = client.delete_table().table_name(table).send().await;
match resp {
Ok(out) => {
println!("Deleted table");
Ok(out)
}
Err(e) => Err(Error::Unhandled(e.into())),
}
}
```
+ 有关 API 详细信息，请参阅《AWS SDK for Rust API Reference》**中的 [DeleteTable](https://docs.rs/aws-sdk-dynamodb/latest/aws_sdk_dynamodb/client/struct.Client.html#method.delete_table)。
------
#### [ SAP ABAP ]
**适用于 SAP ABAP 的 SDK**
查看 GitHub，了解更多信息。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/sap-abap/services/dyn#code-examples)中查找完整示例，了解如何进行设置和运行。
```
TRY.
lo_dyn->deletetable( iv_tablename = iv_table_name ).
" Wait till the table is actually deleted.
lo_dyn->get_waiter( )->tablenotexists(
iv_max_wait_time = 200
iv_tablename = iv_table_name ).
MESSAGE 'Table ' && iv_table_name && ' deleted.' TYPE 'I'.
CATCH /aws1/cx_dynresourcenotfoundex.
MESSAGE 'The table ' && iv_table_name && ' does not exist' TYPE 'E'.
CATCH /aws1/cx_dynresourceinuseex.
MESSAGE 'The table cannot be deleted since it is in use' TYPE 'E'.
ENDTRY.
```
+ 有关 API 详细信息，请参阅《AWS SDK for SAP ABAP API Reference》**中的 [DeleteTable](https://docs.aws.amazon.com/sdk-for-sap-abap/v1/api/latest/index.html)。
------
#### [ Swift ]
**适用于 Swift 的 SDK**
查看 GitHub，了解更多信息。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/swift/example_code/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
```
import AWSDynamoDB
///
/// Deletes the table from Amazon DynamoDB.
///
func deleteTable() async throws {
do {
guard let client = self.ddbClient else {
throw MoviesError.UninitializedClient
}
let input = DeleteTableInput(
tableName: self.tableName
)
_ = try await client.deleteTable(input: input)
} catch {
print("ERROR: deleteTable:", dump(error))
throw error
}
}
```
+ 有关 API 详细信息，请参阅《AWS SDK for Swift API 参考》**中的 [DeleteTable](https://sdk.amazonaws.com/swift/api/awsdynamodb/latest/documentation/awsdynamodb/dynamodbclient/deletetable(input:))。
------
有关 AWS SDK 开发人员指南和代码示例的完整列表，请参阅 [结合使用 DynamoDB 与 AWS SDK](sdk-general-information-section.md) 本主题还包括有关入门的信息以及有关先前的 SDK 版本的详细信息。
# 将 `DescribeTable` 与 AWS SDK 或 CLI 配合使用
以下代码示例演示如何使用 `DescribeTable`。
操作示例是大型程序的代码摘录，必须在上下文中运行。您可以在以下代码示例中查看此操作的上下文：
+ [了解基本功能](example_dynamodb_Scenario_GettingStartedMovies_section.md)
+ [创建和管理用于演示 MREC 的全局表](example_dynamodb_Scenario_GlobalTableOperations_section.md)
+ [创建和管理 MRSC 全局表](example_dynamodb_Scenario_MRSCGlobalTables_section.md)
+ [使用全局表和多区域复制最终一致性（MREC）](example_dynamodb_Scenario_MultiRegionReplication_section.md)
+ [处理 Streams 和生存时间](example_dynamodb_Scenario_StreamsAndTTL_section.md)
+ [处理表加密](example_dynamodb_Scenario_EncryptionExamples_section.md)
------
#### [ .NET ]
**适用于 .NET 的 SDK**
查看 GitHub，了解更多信息。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/dotnetv3/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
```
private static async Task GetTableInformation()
{
Console.WriteLine("\n*** Retrieving table information ***");
var response = await Client.DescribeTableAsync(new DescribeTableRequest
{
TableName = ExampleTableName
});
var table = response.Table;
Console.WriteLine($"Name: {table.TableName}");
Console.WriteLine($"# of items: {table.ItemCount}");
}
```
+ 有关 API 详细信息，请参阅《适用于 .NET 的 AWS SDK API Reference》**中的 [DescribeTable](https://docs.aws.amazon.com/goto/DotNetSDKV3/dynamodb-2012-08-10/DescribeTable)。
------
#### [ Bash ]
**AWS CLI 及 Bash 脚本**
查看 GitHub，了解更多信息。查找完整示例，了解如何在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/aws-cli/bash-linux/dynamodb#code-examples)中进行设置和运行。
```
###############################################################################
# function dynamodb_describe_table
#
# This function returns the status of a DynamoDB table.
#
# Parameters:
# -n table_name -- The name of the table.
#
# Response:
# - TableStatus:
# And:
# 0 - Table is active.
# 1 - If it fails.
###############################################################################
function dynamodb_describe_table {
local table_name
local option OPTARG # Required to use getopts command in a function.
#######################################
# Function usage explanation
#######################################
function usage() {
echo "function dynamodb_describe_table"
echo "Describe the status of a DynamoDB table."
echo " -n table_name -- The name of the table."
echo ""
}
# Retrieve the calling parameters.
while getopts "n:h" option; do
case "${option}" in
n) table_name="${OPTARG}" ;;
h)
usage
return 0
;;
\?)
echo "Invalid parameter"
usage
return 1
;;
esac
done
export OPTIND=1
if [[ -z "$table_name" ]]; then
errecho "ERROR: You must provide a table name with the -n parameter."
usage
return 1
fi
local table_status
table_status=$(
aws dynamodb describe-table \
--table-name "$table_name" \
--output text \
--query 'Table.TableStatus'
)
local error_code=${?}
if [[ $error_code -ne 0 ]]; then
aws_cli_error_log "$error_code"
errecho "ERROR: AWS reports describe-table operation failed.$table_status"
return 1
fi
echo "$table_status"
return 0
}
```
本示例中使用的实用程序函数。
```
###############################################################################
# function errecho
#
# This function outputs everything sent to it to STDERR (standard error output).
###############################################################################
function errecho() {
printf "%s\n" "$*" 1>&2
}
##############################################################################
# function aws_cli_error_log()
#
# This function is used to log the error messages from the AWS CLI.
#
# See https://docs.aws.amazon.com/cli/latest/topic/return-codes.html#cli-aws-help-return-codes.
#
# The function expects the following argument:
# $1 - The error code returned by the AWS CLI.
#
# Returns:
# 0: - Success.
#
##############################################################################
function aws_cli_error_log() {
local err_code=$1
errecho "Error code : $err_code"
if [ "$err_code" == 1 ]; then
errecho " One or more S3 transfers failed."
elif [ "$err_code" == 2 ]; then
errecho " Command line failed to parse."
elif [ "$err_code" == 130 ]; then
errecho " Process received SIGINT."
elif [ "$err_code" == 252 ]; then
errecho " Command syntax invalid."
elif [ "$err_code" == 253 ]; then
errecho " The system environment or configuration was invalid."
elif [ "$err_code" == 254 ]; then
errecho " The service returned an error."
elif [ "$err_code" == 255 ]; then
errecho " 255 is a catch-all error."
fi
return 0
}
```
+ 有关 API 详细信息，请参阅《AWS CLI 命令参考》**中的 [DescribeTable](https://docs.aws.amazon.com/goto/aws-cli/dynamodb-2012-08-10/DescribeTable)。
------
#### [ C\$1\$1 ]
**SDK for C\$1\$1**
查看 GitHub，了解更多信息。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/cpp/example_code/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
```
//! Describe an Amazon DynamoDB table.
/*!
\sa describeTable()
\param tableName: The DynamoDB table name.
\param clientConfiguration: AWS client configuration.
\return bool: Function succeeded.
*/
bool AwsDoc::DynamoDB::describeTable(const Aws::String &tableName,
const Aws::Client::ClientConfiguration &clientConfiguration) {
Aws::DynamoDB::DynamoDBClient dynamoClient(clientConfiguration);
Aws::DynamoDB::Model::DescribeTableRequest request;
request.SetTableName(tableName);
const Aws::DynamoDB::Model::DescribeTableOutcome &outcome = dynamoClient.DescribeTable(
request);
if (outcome.IsSuccess()) {
const Aws::DynamoDB::Model::TableDescription &td = outcome.GetResult().GetTable();
std::cout << "Table name : " << td.GetTableName() << std::endl;
std::cout << "Table ARN : " << td.GetTableArn() << std::endl;
std::cout << "Status : "
<< Aws::DynamoDB::Model::TableStatusMapper::GetNameForTableStatus(
td.GetTableStatus()) << std::endl;
std::cout << "Item count : " << td.GetItemCount() << std::endl;
std::cout << "Size (bytes): " << td.GetTableSizeBytes() << std::endl;
const Aws::DynamoDB::Model::ProvisionedThroughputDescription &ptd = td.GetProvisionedThroughput();
std::cout << "Throughput" << std::endl;
std::cout << " Read Capacity : " << ptd.GetReadCapacityUnits() << std::endl;
std::cout << " Write Capacity: " << ptd.GetWriteCapacityUnits() << std::endl;
const Aws::Vector &ad = td.GetAttributeDefinitions();
std::cout << "Attributes" << std::endl;
for (const auto &a: ad)
std::cout << " " << a.GetAttributeName() << " (" <<
Aws::DynamoDB::Model::ScalarAttributeTypeMapper::GetNameForScalarAttributeType(
a.GetAttributeType()) <<
")" << std::endl;
}
else {
std::cerr << "Failed to describe table: " << outcome.GetError().GetMessage();
}
return outcome.IsSuccess();
}
```
+ 有关 API 详细信息，请参阅《适用于 C\$1\$1 的 AWS SDK API Reference》**中的 [DescribeTable](https://docs.aws.amazon.com/goto/SdkForCpp/dynamodb-2012-08-10/DescribeTable)。
------
#### [ CLI ]
**AWS CLI**
**描述表**
以下 `describe-table` 示例描述 `MusicCollection` 表。
```
aws dynamodb describe-table \
--table-name MusicCollection
```
输出：
```
{
"Table": {
"AttributeDefinitions": [
{
"AttributeName": "Artist",
"AttributeType": "S"
},
{
"AttributeName": "SongTitle",
"AttributeType": "S"
}
],
"ProvisionedThroughput": {
"NumberOfDecreasesToday": 0,
"WriteCapacityUnits": 5,
"ReadCapacityUnits": 5
},
"TableSizeBytes": 0,
"TableName": "MusicCollection",
"TableStatus": "ACTIVE",
"KeySchema": [
{
"KeyType": "HASH",
"AttributeName": "Artist"
},
{
"KeyType": "RANGE",
"AttributeName": "SongTitle"
}
],
"ItemCount": 0,
"CreationDateTime": 1421866952.062
}
}
```
有关更多信息，请参阅《Amazon DynamoDB 开发人员指南》**中的[描述表](https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/WorkingWithTables.Basics.html#WorkingWithTables.Basics.DescribeTable)。
+ 有关 API 详细信息，请参阅《AWS CLI 命令参考》**中的 [DescribeTable](https://awscli.amazonaws.com/v2/documentation/api/latest/reference/dynamodb/describe-table.html)。
------
#### [ Go ]
**适用于 Go 的 SDK V2**
查看 GitHub，了解更多信息。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/gov2/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
```
import (
"context"
"errors"
"log"
"time"
"github.com/aws/aws-sdk-go-v2/aws"
"github.com/aws/aws-sdk-go-v2/feature/dynamodb/attributevalue"
"github.com/aws/aws-sdk-go-v2/feature/dynamodb/expression"
"github.com/aws/aws-sdk-go-v2/service/dynamodb"
"github.com/aws/aws-sdk-go-v2/service/dynamodb/types"
)
// TableBasics encapsulates the Amazon DynamoDB service actions used in the examples.
// It contains a DynamoDB service client that is used to act on the specified table.
type TableBasics struct {
DynamoDbClient *dynamodb.Client
TableName string
}
// TableExists determines whether a DynamoDB table exists.
func (basics TableBasics) TableExists(ctx context.Context) (bool, error) {
exists := true
_, err := basics.DynamoDbClient.DescribeTable(
ctx, &dynamodb.DescribeTableInput{TableName: aws.String(basics.TableName)},
)
if err != nil {
var notFoundEx *types.ResourceNotFoundException
if errors.As(err, ¬FoundEx) {
log.Printf("Table %v does not exist.\n", basics.TableName)
err = nil
} else {
log.Printf("Couldn't determine existence of table %v. Here's why: %v\n", basics.TableName, err)
}
exists = false
}
return exists, err
}
```
+ 有关 API 详细信息，请参阅《适用于 Go 的 AWS SDK API Reference》**中的 [DescribeTable](https://pkg.go.dev/github.com/aws/aws-sdk-go-v2/service/dynamodb#Client.DescribeTable)。
------
#### [ Java ]
**适用于 Java 的 SDK 2.x**
查看 GitHub，了解更多信息。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javav2/example_code/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
```
import software.amazon.awssdk.regions.Region;
import software.amazon.awssdk.services.dynamodb.model.DynamoDbException;
import software.amazon.awssdk.services.dynamodb.DynamoDbClient;
import software.amazon.awssdk.services.dynamodb.model.AttributeDefinition;
import software.amazon.awssdk.services.dynamodb.model.DescribeTableRequest;
import software.amazon.awssdk.services.dynamodb.model.ProvisionedThroughputDescription;
import software.amazon.awssdk.services.dynamodb.model.TableDescription;
import java.util.List;
/**
* Before running this Java V2 code example, set up your development
* environment, including your credentials.
*
* For more information, see the following documentation topic:
*
* https://docs.aws.amazon.com/sdk-for-java/latest/developer-guide/get-started.html
*/
public class DescribeTable {
public static void main(String[] args) {
final String usage = """
Usage:
Where:
tableName - The Amazon DynamoDB table to get information about (for example, Music3).
""";
if (args.length != 1) {
System.out.println(usage);
System.exit(1);
}
String tableName = args[0];
System.out.format("Getting description for %s\n\n", tableName);
Region region = Region.US_EAST_1;
DynamoDbClient ddb = DynamoDbClient.builder()
.region(region)
.build();
describeDymamoDBTable(ddb, tableName);
ddb.close();
}
public static void describeDymamoDBTable(DynamoDbClient ddb, String tableName) {
DescribeTableRequest request = DescribeTableRequest.builder()
.tableName(tableName)
.build();
try {
TableDescription tableInfo = ddb.describeTable(request).table();
if (tableInfo != null) {
System.out.format("Table name : %s\n", tableInfo.tableName());
System.out.format("Table ARN : %s\n", tableInfo.tableArn());
System.out.format("Status : %s\n", tableInfo.tableStatus());
System.out.format("Item count : %d\n", tableInfo.itemCount());
System.out.format("Size (bytes): %d\n", tableInfo.tableSizeBytes());
ProvisionedThroughputDescription throughputInfo = tableInfo.provisionedThroughput();
System.out.println("Throughput");
System.out.format(" Read Capacity : %d\n", throughputInfo.readCapacityUnits());
System.out.format(" Write Capacity: %d\n", throughputInfo.writeCapacityUnits());
List attributes = tableInfo.attributeDefinitions();
System.out.println("Attributes");
for (AttributeDefinition a : attributes) {
System.out.format(" %s (%s)\n", a.attributeName(), a.attributeType());
}
}
} catch (DynamoDbException e) {
System.err.println(e.getMessage());
System.exit(1);
}
System.out.println("\nDone!");
}
}
```
+ 有关 API 详细信息，请参阅《AWS SDK for Java 2.x API Reference》**中的 [DescribeTable](https://docs.aws.amazon.com/goto/SdkForJavaV2/dynamodb-2012-08-10/DescribeTable)。
------
#### [ JavaScript ]
**SDK for JavaScript (v3)**
查看 GitHub，了解更多信息。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javascriptv3/example_code/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
```
import { DescribeTableCommand, DynamoDBClient } from "@aws-sdk/client-dynamodb";
const client = new DynamoDBClient({});
export const main = async () => {
const command = new DescribeTableCommand({
TableName: "Pastries",
});
const response = await client.send(command);
console.log(`TABLE NAME: ${response.Table.TableName}`);
console.log(`TABLE ITEM COUNT: ${response.Table.ItemCount}`);
return response;
};
```
+ 有关更多信息，请参阅《适用于 JavaScript 的 AWS SDK 开发人员指南》[https://docs.aws.amazon.com/sdk-for-javascript/v3/developer-guide/dynamodb-examples-using-tables.html#dynamodb-examples-using-tables-describing-a-table](https://docs.aws.amazon.com/sdk-for-javascript/v3/developer-guide/dynamodb-examples-using-tables.html#dynamodb-examples-using-tables-describing-a-table)。
+ 有关 API 详细信息，请参阅《适用于 JavaScript 的 AWS SDK API Reference》**中的 [DescribeTable](https://docs.aws.amazon.com/AWSJavaScriptSDK/v3/latest/client/dynamodb/command/DescribeTableCommand)。
**SDK for JavaScript (v2)**
查看 GitHub，了解更多信息。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javascript/example_code/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
```
// Load the AWS SDK for Node.js
var AWS = require("aws-sdk");
// Set the region
AWS.config.update({ region: "REGION" });
// Create the DynamoDB service object
var ddb = new AWS.DynamoDB({ apiVersion: "2012-08-10" });
var params = {
TableName: process.argv[2],
};
// Call DynamoDB to retrieve the selected table descriptions
ddb.describeTable(params, function (err, data) {
if (err) {
console.log("Error", err);
} else {
console.log("Success", data.Table.KeySchema);
}
});
```
+ 有关更多信息，请参阅《适用于 JavaScript 的 AWS SDK 开发人员指南》[https://docs.aws.amazon.com/sdk-for-javascript/v2/developer-guide/dynamodb-examples-using-tables.html#dynamodb-examples-using-tables-describing-a-table](https://docs.aws.amazon.com/sdk-for-javascript/v2/developer-guide/dynamodb-examples-using-tables.html#dynamodb-examples-using-tables-describing-a-table)。
+ 有关 API 详细信息，请参阅《适用于 JavaScript 的 AWS SDK API Reference》**中的 [DescribeTable](https://docs.aws.amazon.com/goto/AWSJavaScriptSDK/dynamodb-2012-08-10/DescribeTable)。
------
#### [ PowerShell ]
**适用于 PowerShell V4 的工具**
**示例 1：返回指定表的详细信息。**
```
Get-DDBTable -TableName "myTable"
```
+ 有关 API 详细信息，请参阅《AWS Tools for PowerShell Cmdlet Reference (V4)》**中的 [DescribeTable](https://docs.aws.amazon.com/powershell/v4/reference)。
**适用于 PowerShell V5 的工具**
**示例 1：返回指定表的详细信息。**
```
Get-DDBTable -TableName "myTable"
```
+ 有关 API 详细信息，请参阅《AWS Tools for PowerShell Cmdlet Reference (V5)》**中的 [DescribeTable](https://docs.aws.amazon.com/powershell/v5/reference)。
------
#### [ Python ]
**适用于 Python 的 SDK（Boto3）**
查看 GitHub，了解更多信息。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/python/example_code/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
```
class Movies:
"""Encapsulates an Amazon DynamoDB table of movie data.
Example data structure for a movie record in this table:
{
"year": 1999,
"title": "For Love of the Game",
"info": {
"directors": ["Sam Raimi"],
"release_date": "1999-09-15T00:00:00Z",
"rating": 6.3,
"plot": "A washed up pitcher flashes through his career.",
"rank": 4987,
"running_time_secs": 8220,
"actors": [
"Kevin Costner",
"Kelly Preston",
"John C. Reilly"
]
}
}
"""
def __init__(self, dyn_resource):
"""
:param dyn_resource: A Boto3 DynamoDB resource.
"""
self.dyn_resource = dyn_resource
# The table variable is set during the scenario in the call to
# 'exists' if the table exists. Otherwise, it is set by 'create_table'.
self.table = None
def exists(self, table_name):
"""
Determines whether a table exists. As a side effect, stores the table in
a member variable.
:param table_name: The name of the table to check.
:return: True when the table exists; otherwise, False.
"""
try:
table = self.dyn_resource.Table(table_name)
table.load()
exists = True
except ClientError as err:
if err.response["Error"]["Code"] == "ResourceNotFoundException":
exists = False
else:
logger.error(
"Couldn't check for existence of %s. Here's why: %s: %s",
table_name,
err.response["Error"]["Code"],
err.response["Error"]["Message"],
)
raise
else:
self.table = table
return exists
```
+ 有关 API 详细信息，请参阅《AWS SDK for Python (Boto3) API Reference》**中的 [DescribeTable](https://docs.aws.amazon.com/goto/boto3/dynamodb-2012-08-10/DescribeTable)。
------
#### [ Ruby ]
**适用于 Ruby 的 SDK**
查看 GitHub，了解更多信息。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/ruby/example_code/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
```
# Encapsulates an Amazon DynamoDB table of movie data.
class Scaffold
attr_reader :dynamo_resource, :table_name, :table
def initialize(table_name)
client = Aws::DynamoDB::Client.new(region: 'us-east-1')
@dynamo_resource = Aws::DynamoDB::Resource.new(client: client)
@table_name = table_name
@table = nil
@logger = Logger.new($stdout)
@logger.level = Logger::DEBUG
end
# Determines whether a table exists. As a side effect, stores the table in
# a member variable.
#
# @param table_name [String] The name of the table to check.
# @return [Boolean] True when the table exists; otherwise, False.
def exists?(table_name)
@dynamo_resource.client.describe_table(table_name: table_name)
@logger.debug("Table #{table_name} exists")
rescue Aws::DynamoDB::Errors::ResourceNotFoundException
@logger.debug("Table #{table_name} doesn't exist")
false
rescue Aws::DynamoDB::Errors::ServiceError => e
puts("Couldn't check for existence of #{table_name}:\n")
puts("\t#{e.code}: #{e.message}")
raise
end
```
+ 有关 API 详细信息，请参阅《适用于 Ruby 的 AWS SDK API Reference》**中的 [DescribeTable](https://docs.aws.amazon.com/goto/SdkForRubyV3/dynamodb-2012-08-10/DescribeTable)。
------
#### [ SAP ABAP ]
**适用于 SAP ABAP 的 SDK**
查看 GitHub，了解更多信息。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/sap-abap/services/dyn#code-examples)中查找完整示例，了解如何进行设置和运行。
```
TRY.
oo_result = lo_dyn->describetable( iv_tablename = iv_table_name ).
DATA(lv_tablename) = oo_result->get_table( )->ask_tablename( ).
DATA(lv_tablearn) = oo_result->get_table( )->ask_tablearn( ).
DATA(lv_tablestatus) = oo_result->get_table( )->ask_tablestatus( ).
DATA(lv_itemcount) = oo_result->get_table( )->ask_itemcount( ).
MESSAGE 'The table name is ' && lv_tablename
&& '. The table ARN is ' && lv_tablearn
&& '. The tablestatus is ' && lv_tablestatus
&& '. Item count is ' && lv_itemcount TYPE 'I'.
CATCH /aws1/cx_dynresourcenotfoundex.
MESSAGE 'The table ' && lv_tablename && ' does not exist' TYPE 'E'.
ENDTRY.
```
+ 有关 API 详细信息，请参阅《适用于 SAP ABAP 的 AWS SDK API 参考》**中的 [DescribeTable](https://docs.aws.amazon.com/sdk-for-sap-abap/v1/api/latest/index.html)。
------
有关 AWS SDK 开发人员指南和代码示例的完整列表，请参阅 [结合使用 DynamoDB 与 AWS SDK](sdk-general-information-section.md) 本主题还包括有关入门的信息以及有关先前的 SDK 版本的详细信息。
# 将 `DescribeTimeToLive` 与 AWS SDK 或 CLI 配合使用
以下代码示例演示如何使用 `DescribeTimeToLive`。
操作示例是大型程序的代码摘录，必须在上下文中运行。在以下代码示例中，您可以查看此操作的上下文：
+ [处理 Streams 和生存时间](example_dynamodb_Scenario_StreamsAndTTL_section.md)
------
#### [ CLI ]
**AWS CLI**
**查看表的生存时间设置**
以下 `describe-time-to-live` 示例显示 `MusicCollection` 表的生存时间设置。
```
aws dynamodb describe-time-to-live \
--table-name MusicCollection
```
输出：
```
{
"TimeToLiveDescription": {
"TimeToLiveStatus": "ENABLED",
"AttributeName": "ttl"
}
}
```
有关更多信息，请参阅《Amazon DynamoDB 开发人员指南》**中的[生存时间](https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/TTL.html)。
+ 有关 API 详细信息，请参阅《AWS CLI 命令参考》**中的 [DescribeTimeToLive](https://awscli.amazonaws.com/v2/documentation/api/latest/reference/dynamodb/describe-time-to-live.html)。
------
#### [ Java ]
**适用于 Java 的 SDK 2.x**
使用AWS SDK for Java 2.x 描述现有 DynamoDB 表上的 TTL 配置。
```
import software.amazon.awssdk.regions.Region;
import software.amazon.awssdk.services.dynamodb.DynamoDbClient;
import software.amazon.awssdk.services.dynamodb.model.DescribeTimeToLiveRequest;
import software.amazon.awssdk.services.dynamodb.model.DescribeTimeToLiveResponse;
import software.amazon.awssdk.services.dynamodb.model.DynamoDbException;
import software.amazon.awssdk.services.dynamodb.model.ResourceNotFoundException;
import java.util.logging.Level;
import java.util.logging.Logger;
public DescribeTimeToLiveResponse describeTTL(final String tableName, final Region region) {
final DescribeTimeToLiveRequest request =
DescribeTimeToLiveRequest.builder().tableName(tableName).build();
try (DynamoDbClient ddb = dynamoDbClient != null
? dynamoDbClient
: DynamoDbClient.builder().region(region).build()) {
return ddb.describeTimeToLive(request);
} catch (ResourceNotFoundException e) {
System.err.format(TABLE_NOT_FOUND_ERROR, tableName);
throw e;
} catch (DynamoDbException e) {
System.err.println(e.getMessage());
throw e;
}
}
```
+ 有关 API 详细信息，请参阅《AWS SDK for Java 2.x API Reference》**中的 [DescribeTimeToLive](https://docs.aws.amazon.com/goto/SdkForJavaV2/dynamodb-2012-08-10/DescribeTimeToLive)。
------
#### [ JavaScript ]
**SDK for JavaScript（v3）**
使用适用于 JavaScript 的 AWS SDK 描述现有 DynamoDB 表上的 TTL 配置。
```
import { DynamoDBClient, DescribeTimeToLiveCommand } from "@aws-sdk/client-dynamodb";
export const describeTTL = async (tableName, region) => {
const client = new DynamoDBClient({
region: region,
endpoint: `https://dynamodb.${region}.amazonaws.com`
});
try {
const ttlDescription = await client.send(new DescribeTimeToLiveCommand({ TableName: tableName }));
if (ttlDescription.TimeToLiveDescription.TimeToLiveStatus === 'ENABLED') {
console.log("TTL is enabled for table %s.", tableName);
} else {
console.log("TTL is not enabled for table %s.", tableName);
}
return ttlDescription;
} catch (e) {
console.error(`Error describing table: ${e}`);
throw e;
}
}
// Example usage (commented out for testing)
// describeTTL('your-table-name', 'us-east-1');
```
+ 有关 API 详细信息，请参阅《适用于 JavaScript 的 AWS SDK API Reference》**中的 [DescribeTimeToLive](https://docs.aws.amazon.com/AWSJavaScriptSDK/v3/latest/client/dynamodb/command/DescribeTimeToLiveCommand)。
------
#### [ Python ]
**适用于 Python 的 SDK（Boto3）**
使用适用于 Python (Boto3) 的 AWS SDK 描述现有 DynamoDB 表上的 TTL 配置。
```
import boto3
def describe_ttl(table_name, region):
"""
Describes TTL on an existing table, as well as a region.
:param table_name: String representing the name of the table
:param region: AWS Region of the table - example `us-east-1`
:return: Time to live description.
"""
try:
dynamodb = boto3.resource("dynamodb", region_name=region)
ttl_description = dynamodb.describe_time_to_live(TableName=table_name)
print(
f"TimeToLive for table {table_name} is status {ttl_description['TimeToLiveDescription']['TimeToLiveStatus']}"
)
return ttl_description
except Exception as e:
print(f"Error describing table: {e}")
raise
# Enter your own table name and AWS region
describe_ttl("your-table-name", "us-east-1")
```
+ 有关 API 详细信息，请参阅《AWS SDK for Python (Boto3) API Reference》**中的 [DescribeTimeToLive](https://docs.aws.amazon.com/goto/boto3/dynamodb-2012-08-10/DescribeTimeToLive)。
------
有关 AWS SDK 开发人员指南和代码示例的完整列表，请参阅 [结合使用 DynamoDB 与 AWS SDK](sdk-general-information-section.md) 本主题还包括有关入门的信息以及有关先前的 SDK 版本的详细信息。
# 将 `ExecuteStatement` 和 AWS SDK 搭配使用
以下代码示例演示如何使用 `ExecuteStatement`。
操作示例是大型程序的代码摘录，必须在上下文中运行。您可以在以下代码示例中查看此操作的上下文：
+ [使用 PartiQL DELETE 删除数据](example_dynamodb_PartiQLDelete_section.md)
+ [使用 PartiQL INSERT 插入数据](example_dynamodb_PartiQLInsert_section.md)
+ [使用 PartiQL 查询表](example_dynamodb_Scenario_PartiQLSingle_section.md)
+ [使用 PartiQL SELECT 查询数据](example_dynamodb_PartiQLSelect_section.md)
+ [使用 PartiQL UPDATE 更新数据](example_dynamodb_PartiQLUpdate_section.md)
------
#### [ .NET ]
**适用于 .NET 的 SDK**
查看 GitHub，了解更多信息。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/dotnetv3/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
使用 INSERT 语句添加项目。
```
///
/// Inserts a single movie into the movies table.
///
/// The name of the table.
/// The title of the movie to insert.
/// The year that the movie was released.
/// A Boolean value that indicates the success or failure of
/// the INSERT operation.
public static async Task InsertSingleMovie(string tableName, string movieTitle, int year)
{
string insertBatch = $"INSERT INTO {tableName} VALUE {{'title': ?, 'year': ?}}";
var response = await Client.ExecuteStatementAsync(new ExecuteStatementRequest
{
Statement = insertBatch,
Parameters = new List
{
new AttributeValue { S = movieTitle },
new AttributeValue { N = year.ToString() },
},
});
return response.HttpStatusCode == System.Net.HttpStatusCode.OK;
}
```
使用 SELECT 语句获取项目。
```
///
/// Uses a PartiQL SELECT statement to retrieve a single movie from the
/// movie database.
///
/// The name of the movie table.
/// The title of the movie to retrieve.
/// A list of movie data. If no movie matches the supplied
/// title, the list is empty.
public static async Task>> GetSingleMovie(string tableName, string movieTitle)
{
string selectSingle = $"SELECT * FROM {tableName} WHERE title = ?";
var parameters = new List
{
new AttributeValue { S = movieTitle },
};
var response = await Client.ExecuteStatementAsync(new ExecuteStatementRequest
{
Statement = selectSingle,
Parameters = parameters,
});
return response.Items;
}
```
使用 SELECT 语句获取项目列表。
```
///
/// Retrieve multiple movies by year using a SELECT statement.
///
/// The name of the movie table.
/// The year the movies were released.
///
public static async Task>> GetMovies(string tableName, int year)
{
string selectSingle = $"SELECT * FROM {tableName} WHERE year = ?";
var parameters = new List
{
new AttributeValue { N = year.ToString() },
};
var response = await Client.ExecuteStatementAsync(new ExecuteStatementRequest
{
Statement = selectSingle,
Parameters = parameters,
});
return response.Items;
}
```
使用 UPDATE 语句更新项目。
```
///
/// Updates a single movie in the table, adding information for the
/// producer.
///
/// the name of the table.
/// The name of the producer.
/// The movie title.
/// The year the movie was released.
/// A Boolean value that indicates the success of the
/// UPDATE operation.
public static async Task UpdateSingleMovie(string tableName, string producer, string movieTitle, int year)
{
string insertSingle = $"UPDATE {tableName} SET Producer=? WHERE title = ? AND year = ?";
var response = await Client.ExecuteStatementAsync(new ExecuteStatementRequest
{
Statement = insertSingle,
Parameters = new List
{
new AttributeValue { S = producer },
new AttributeValue { S = movieTitle },
new AttributeValue { N = year.ToString() },
},
});
return response.HttpStatusCode == System.Net.HttpStatusCode.OK;
}
```
使用 DELETE 语句删除单个电影。
```
///
/// Deletes a single movie from the table.
///
/// The name of the table.
/// The title of the movie to delete.
/// The year that the movie was released.
/// A Boolean value that indicates the success of the
/// DELETE operation.
public static async Task DeleteSingleMovie(string tableName, string movieTitle, int year)
{
var deleteSingle = $"DELETE FROM {tableName} WHERE title = ? AND year = ?";
var response = await Client.ExecuteStatementAsync(new ExecuteStatementRequest
{
Statement = deleteSingle,
Parameters = new List
{
new AttributeValue { S = movieTitle },
new AttributeValue { N = year.ToString() },
},
});
return response.HttpStatusCode == System.Net.HttpStatusCode.OK;
}
```
+ 有关 API 详细信息，请参阅《适用于 .NET 的 AWS SDK API Reference》**中的 [ExecuteStatement](https://docs.aws.amazon.com/goto/DotNetSDKV3/dynamodb-2012-08-10/ExecuteStatement)。
------
#### [ C\$1\$1 ]
**SDK for C\$1\$1**
查看 GitHub，了解更多信息。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/cpp/example_code/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
使用 INSERT 语句添加项目。
```
Aws::DynamoDB::DynamoDBClient dynamoClient(clientConfiguration);
// 2. Add a new movie using an "Insert" statement. (ExecuteStatement)
Aws::String title;
float rating;
int year;
Aws::String plot;
{
title = askQuestion(
"Enter the title of a movie you want to add to the table: ");
year = askQuestionForInt("What year was it released? ");
rating = askQuestionForFloatRange("On a scale of 1 - 10, how do you rate it? ",
1, 10);
plot = askQuestion("Summarize the plot for me: ");
Aws::DynamoDB::Model::ExecuteStatementRequest request;
std::stringstream sqlStream;
sqlStream << "INSERT INTO \"" << MOVIE_TABLE_NAME << "\" VALUE {'"
<< TITLE_KEY << "': ?, '" << YEAR_KEY << "': ?, '"
<< INFO_KEY << "': ?}";
request.SetStatement(sqlStream.str());
// Create the parameter attributes.
Aws::Vector attributes;
attributes.push_back(Aws::DynamoDB::Model::AttributeValue().SetS(title));
attributes.push_back(Aws::DynamoDB::Model::AttributeValue().SetN(year));
Aws::DynamoDB::Model::AttributeValue infoMapAttribute;
std::shared_ptr ratingAttribute = Aws::MakeShared(
ALLOCATION_TAG.c_str());
ratingAttribute->SetN(rating);
infoMapAttribute.AddMEntry(RATING_KEY, ratingAttribute);
std::shared_ptr plotAttribute = Aws::MakeShared(
ALLOCATION_TAG.c_str());
plotAttribute->SetS(plot);
infoMapAttribute.AddMEntry(PLOT_KEY, plotAttribute);
attributes.push_back(infoMapAttribute);
request.SetParameters(attributes);
Aws::DynamoDB::Model::ExecuteStatementOutcome outcome = dynamoClient.ExecuteStatement(
request);
if (!outcome.IsSuccess()) {
std::cerr << "Failed to add a movie: " << outcome.GetError().GetMessage()
<< std::endl;
return false;
}
}
```
使用 SELECT 语句获取项目。
```
// 3. Get the data for the movie using a "Select" statement. (ExecuteStatement)
{
Aws::DynamoDB::Model::ExecuteStatementRequest request;
std::stringstream sqlStream;
sqlStream << "SELECT * FROM \"" << MOVIE_TABLE_NAME << "\" WHERE "
<< TITLE_KEY << "=? and " << YEAR_KEY << "=?";
request.SetStatement(sqlStream.str());
Aws::Vector attributes;
attributes.push_back(Aws::DynamoDB::Model::AttributeValue().SetS(title));
attributes.push_back(Aws::DynamoDB::Model::AttributeValue().SetN(year));
request.SetParameters(attributes);
Aws::DynamoDB::Model::ExecuteStatementOutcome outcome = dynamoClient.ExecuteStatement(
request);
if (!outcome.IsSuccess()) {
std::cerr << "Failed to retrieve movie information: "
<< outcome.GetError().GetMessage() << std::endl;
return false;
}
else {
// Print the retrieved movie information.
const Aws::DynamoDB::Model::ExecuteStatementResult &result = outcome.GetResult();
const Aws::Vector> &items = result.GetItems();
if (items.size() == 1) {
printMovieInfo(items[0]);
}
else {
std::cerr << "Error: " << items.size() << " movies were retrieved. "
<< " There should be only one movie." << std::endl;
}
}
}
```
使用 UPDATE 语句更新项目。
```
// 4. Update the data for the movie using an "Update" statement. (ExecuteStatement)
{
rating = askQuestionForFloatRange(
Aws::String("\nLet's update your movie.\nYou rated it ") +
std::to_string(rating)
+ ", what new rating would you give it? ", 1, 10);
Aws::DynamoDB::Model::ExecuteStatementRequest request;
std::stringstream sqlStream;
sqlStream << "UPDATE \"" << MOVIE_TABLE_NAME << "\" SET "
<< INFO_KEY << "." << RATING_KEY << "=? WHERE "
<< TITLE_KEY << "=? AND " << YEAR_KEY << "=?";
request.SetStatement(sqlStream.str());
Aws::Vector attributes;
attributes.push_back(Aws::DynamoDB::Model::AttributeValue().SetN(rating));
attributes.push_back(Aws::DynamoDB::Model::AttributeValue().SetS(title));
attributes.push_back(Aws::DynamoDB::Model::AttributeValue().SetN(year));
request.SetParameters(attributes);
Aws::DynamoDB::Model::ExecuteStatementOutcome outcome = dynamoClient.ExecuteStatement(
request);
if (!outcome.IsSuccess()) {
std::cerr << "Failed to update a movie: "
<< outcome.GetError().GetMessage();
return false;
}
}
```
使用 DELETE 语句删除项目。
```
// 6. Delete the movie using a "Delete" statement. (ExecuteStatement)
{
Aws::DynamoDB::Model::ExecuteStatementRequest request;
std::stringstream sqlStream;
sqlStream << "DELETE FROM \"" << MOVIE_TABLE_NAME << "\" WHERE "
<< TITLE_KEY << "=? and " << YEAR_KEY << "=?";
request.SetStatement(sqlStream.str());
Aws::Vector attributes;
attributes.push_back(Aws::DynamoDB::Model::AttributeValue().SetS(title));
attributes.push_back(Aws::DynamoDB::Model::AttributeValue().SetN(year));
request.SetParameters(attributes);
Aws::DynamoDB::Model::ExecuteStatementOutcome outcome = dynamoClient.ExecuteStatement(
request);
if (!outcome.IsSuccess()) {
std::cerr << "Failed to delete the movie: "
<< outcome.GetError().GetMessage() << std::endl;
return false;
}
}
```
+ 有关 API 详细信息，请参阅《适用于 C\$1\$1 的 AWS SDK API Reference》**中的 [ExecuteStatement](https://docs.aws.amazon.com/goto/SdkForCpp/dynamodb-2012-08-10/ExecuteStatement)。
------
#### [ Go ]
**适用于 Go 的 SDK V2**
查看 GitHub，了解更多信息。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/gov2/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
为示例定义函数接收器结构。
```
import (
"context"
"fmt"
"log"
"github.com/aws/aws-sdk-go-v2/aws"
"github.com/aws/aws-sdk-go-v2/feature/dynamodb/attributevalue"
"github.com/aws/aws-sdk-go-v2/service/dynamodb"
"github.com/aws/aws-sdk-go-v2/service/dynamodb/types"
)
// PartiQLRunner encapsulates the Amazon DynamoDB service actions used in the
// PartiQL examples. It contains a DynamoDB service client that is used to act on the
// specified table.
type PartiQLRunner struct {
DynamoDbClient *dynamodb.Client
TableName string
}
```
使用 INSERT 语句添加项目。
```
// AddMovie runs a PartiQL INSERT statement to add a movie to the DynamoDB table.
func (runner PartiQLRunner) AddMovie(ctx context.Context, movie Movie) error {
params, err := attributevalue.MarshalList([]interface{}{movie.Title, movie.Year, movie.Info})
if err != nil {
panic(err)
}
_, err = runner.DynamoDbClient.ExecuteStatement(ctx, &dynamodb.ExecuteStatementInput{
Statement: aws.String(
fmt.Sprintf("INSERT INTO \"%v\" VALUE {'title': ?, 'year': ?, 'info': ?}",
runner.TableName)),
Parameters: params,
})
if err != nil {
log.Printf("Couldn't insert an item with PartiQL. Here's why: %v\n", err)
}
return err
}
```
使用 SELECT 语句获取项目。
```
// GetMovie runs a PartiQL SELECT statement to get a movie from the DynamoDB table by
// title and year.
func (runner PartiQLRunner) GetMovie(ctx context.Context, title string, year int) (Movie, error) {
var movie Movie
params, err := attributevalue.MarshalList([]interface{}{title, year})
if err != nil {
panic(err)
}
response, err := runner.DynamoDbClient.ExecuteStatement(ctx, &dynamodb.ExecuteStatementInput{
Statement: aws.String(
fmt.Sprintf("SELECT * FROM \"%v\" WHERE title=? AND year=?",
runner.TableName)),
Parameters: params,
})
if err != nil {
log.Printf("Couldn't get info about %v. Here's why: %v\n", title, err)
} else {
err = attributevalue.UnmarshalMap(response.Items[0], &movie)
if err != nil {
log.Printf("Couldn't unmarshal response. Here's why: %v\n", err)
}
}
return movie, err
}
```
使用 SELECT 语句获取项目列表并预测结果。
```
// GetAllMovies runs a PartiQL SELECT statement to get all movies from the DynamoDB table.
// pageSize is not typically required and is used to show how to paginate the results.
// The results are projected to return only the title and rating of each movie.
func (runner PartiQLRunner) GetAllMovies(ctx context.Context, pageSize int32) ([]map[string]interface{}, error) {
var output []map[string]interface{}
var response *dynamodb.ExecuteStatementOutput
var err error
var nextToken *string
for moreData := true; moreData; {
response, err = runner.DynamoDbClient.ExecuteStatement(ctx, &dynamodb.ExecuteStatementInput{
Statement: aws.String(
fmt.Sprintf("SELECT title, info.rating FROM \"%v\"", runner.TableName)),
Limit: aws.Int32(pageSize),
NextToken: nextToken,
})
if err != nil {
log.Printf("Couldn't get movies. Here's why: %v\n", err)
moreData = false
} else {
var pageOutput []map[string]interface{}
err = attributevalue.UnmarshalListOfMaps(response.Items, &pageOutput)
if err != nil {
log.Printf("Couldn't unmarshal response. Here's why: %v\n", err)
} else {
log.Printf("Got a page of length %v.\n", len(response.Items))
output = append(output, pageOutput...)
}
nextToken = response.NextToken
moreData = nextToken != nil
}
}
return output, err
}
```
使用 UPDATE 语句更新项目。
```
// UpdateMovie runs a PartiQL UPDATE statement to update the rating of a movie that
// already exists in the DynamoDB table.
func (runner PartiQLRunner) UpdateMovie(ctx context.Context, movie Movie, rating float64) error {
params, err := attributevalue.MarshalList([]interface{}{rating, movie.Title, movie.Year})
if err != nil {
panic(err)
}
_, err = runner.DynamoDbClient.ExecuteStatement(ctx, &dynamodb.ExecuteStatementInput{
Statement: aws.String(
fmt.Sprintf("UPDATE \"%v\" SET info.rating=? WHERE title=? AND year=?",
runner.TableName)),
Parameters: params,
})
if err != nil {
log.Printf("Couldn't update movie %v. Here's why: %v\n", movie.Title, err)
}
return err
}
```
使用 DELETE 语句删除项目。
```
// DeleteMovie runs a PartiQL DELETE statement to remove a movie from the DynamoDB table.
func (runner PartiQLRunner) DeleteMovie(ctx context.Context, movie Movie) error {
params, err := attributevalue.MarshalList([]interface{}{movie.Title, movie.Year})
if err != nil {
panic(err)
}
_, err = runner.DynamoDbClient.ExecuteStatement(ctx, &dynamodb.ExecuteStatementInput{
Statement: aws.String(
fmt.Sprintf("DELETE FROM \"%v\" WHERE title=? AND year=?",
runner.TableName)),
Parameters: params,
})
if err != nil {
log.Printf("Couldn't delete %v from the table. Here's why: %v\n", movie.Title, err)
}
return err
}
```
定义本示例中使用的 Movie 结构。
```
import (
"archive/zip"
"bytes"
"encoding/json"
"fmt"
"io"
"log"
"net/http"
"github.com/aws/aws-sdk-go-v2/feature/dynamodb/attributevalue"
"github.com/aws/aws-sdk-go-v2/service/dynamodb/types"
)
// Movie encapsulates data about a movie. Title and Year are the composite primary key
// of the movie in Amazon DynamoDB. Title is the sort key, Year is the partition key,
// and Info is additional data.
type Movie struct {
Title string `dynamodbav:"title"`
Year int `dynamodbav:"year"`
Info map[string]interface{} `dynamodbav:"info"`
}
// GetKey returns the composite primary key of the movie in a format that can be
// sent to DynamoDB.
func (movie Movie) GetKey() map[string]types.AttributeValue {
title, err := attributevalue.Marshal(movie.Title)
if err != nil {
panic(err)
}
year, err := attributevalue.Marshal(movie.Year)
if err != nil {
panic(err)
}
return map[string]types.AttributeValue{"title": title, "year": year}
}
// String returns the title, year, rating, and plot of a movie, formatted for the example.
func (movie Movie) String() string {
return fmt.Sprintf("%v\n\tReleased: %v\n\tRating: %v\n\tPlot: %v\n",
movie.Title, movie.Year, movie.Info["rating"], movie.Info["plot"])
}
```
+ 有关 API 详细信息，请参阅《适用于 Go 的 AWS SDK API Reference》**中的 [ExecuteStatement](https://pkg.go.dev/github.com/aws/aws-sdk-go-v2/service/dynamodb#Client.ExecuteStatement)。
------
#### [ JavaScript ]
**SDK for JavaScript (v3)**
查看 GitHub，了解更多信息。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javascriptv3/example_code/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
使用 PartiQL 创建项目。
```
import { DynamoDBClient } from "@aws-sdk/client-dynamodb";
import {
ExecuteStatementCommand,
DynamoDBDocumentClient,
} from "@aws-sdk/lib-dynamodb";
const client = new DynamoDBClient({});
const docClient = DynamoDBDocumentClient.from(client);
export const main = async () => {
const command = new ExecuteStatementCommand({
Statement: `INSERT INTO Flowers value {'Name':?}`,
Parameters: ["Rose"],
});
const response = await docClient.send(command);
console.log(response);
return response;
};
```
使用 PartiQL 获取项目。
```
import { DynamoDBClient } from "@aws-sdk/client-dynamodb";
import {
ExecuteStatementCommand,
DynamoDBDocumentClient,
} from "@aws-sdk/lib-dynamodb";
const client = new DynamoDBClient({});
const docClient = DynamoDBDocumentClient.from(client);
export const main = async () => {
const command = new ExecuteStatementCommand({
Statement: "SELECT * FROM CloudTypes WHERE IsStorm=?",
Parameters: [false],
ConsistentRead: true,
});
const response = await docClient.send(command);
console.log(response);
return response;
};
```
使用 PartiQL 更新项目。
```
import { DynamoDBClient } from "@aws-sdk/client-dynamodb";
import {
ExecuteStatementCommand,
DynamoDBDocumentClient,
} from "@aws-sdk/lib-dynamodb";
const client = new DynamoDBClient({});
const docClient = DynamoDBDocumentClient.from(client);
export const main = async () => {
const command = new ExecuteStatementCommand({
Statement: "UPDATE EyeColors SET IsRecessive=? where Color=?",
Parameters: [true, "blue"],
});
const response = await docClient.send(command);
console.log(response);
return response;
};
```
使用 PartiQL 删除项目。
```
import { DynamoDBClient } from "@aws-sdk/client-dynamodb";
import {
ExecuteStatementCommand,
DynamoDBDocumentClient,
} from "@aws-sdk/lib-dynamodb";
const client = new DynamoDBClient({});
const docClient = DynamoDBDocumentClient.from(client);
export const main = async () => {
const command = new ExecuteStatementCommand({
Statement: "DELETE FROM PaintColors where Name=?",
Parameters: ["Purple"],
});
const response = await docClient.send(command);
console.log(response);
return response;
};
```
+ 有关 API 详细信息，请参阅《适用于 JavaScript 的 AWS SDK API Reference》**中的 [ExecuteStatement](https://docs.aws.amazon.com/AWSJavaScriptSDK/v3/latest/client/dynamodb/command/ExecuteStatementCommand)。
------
#### [ PHP ]
**适用于 PHP 的 SDK**
查看 GitHub，了解更多信息。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/php/example_code/dynamodb#code-examples) 中查找完整示例，了解如何进行设置和运行。
```
public function insertItemByPartiQL(string $statement, array $parameters)
{
$this->dynamoDbClient->executeStatement([
'Statement' => "$statement",
'Parameters' => $parameters,
]);
}
public function getItemByPartiQL(string $tableName, array $key): Result
{
list($statement, $parameters) = $this->buildStatementAndParameters("SELECT", $tableName, $key['Item']);
return $this->dynamoDbClient->executeStatement([
'Parameters' => $parameters,
'Statement' => $statement,
]);
}
public function updateItemByPartiQL(string $statement, array $parameters)
{
$this->dynamoDbClient->executeStatement([
'Statement' => $statement,
'Parameters' => $parameters,
]);
}
public function deleteItemByPartiQL(string $statement, array $parameters)
{
$this->dynamoDbClient->executeStatement([
'Statement' => $statement,
'Parameters' => $parameters,
]);
}
```
+ 有关 API 详细信息，请参阅《适用于 PHP 的 AWS SDK API Reference》**中的 [ExecuteStatement](https://docs.aws.amazon.com/goto/SdkForPHPV3/dynamodb-2012-08-10/ExecuteStatement)。
------
#### [ Python ]
**适用于 Python 的 SDK（Boto3）**
查看 GitHub，了解更多信息。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/python/example_code/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
```
class PartiQLWrapper:
"""
Encapsulates a DynamoDB resource to run PartiQL statements.
"""
def __init__(self, dyn_resource):
"""
:param dyn_resource: A Boto3 DynamoDB resource.
"""
self.dyn_resource = dyn_resource
def run_partiql(self, statement, params):
"""
Runs a PartiQL statement. A Boto3 resource is used even though
`execute_statement` is called on the underlying `client` object because the
resource transforms input and output from plain old Python objects (POPOs) to
the DynamoDB format. If you create the client directly, you must do these
transforms yourself.
:param statement: The PartiQL statement.
:param params: The list of PartiQL parameters. These are applied to the
statement in the order they are listed.
:return: The items returned from the statement, if any.
"""
try:
output = self.dyn_resource.meta.client.execute_statement(
Statement=statement, Parameters=params
)
except ClientError as err:
if err.response["Error"]["Code"] == "ResourceNotFoundException":
logger.error(
"Couldn't execute PartiQL '%s' because the table does not exist.",
statement,
)
else:
logger.error(
"Couldn't execute PartiQL '%s'. Here's why: %s: %s",
statement,
err.response["Error"]["Code"],
err.response["Error"]["Message"],
)
raise
else:
return output
```
+ 有关 API 详细信息，请参阅《AWS SDK for Python (Boto3) API Reference》**中的 [ExecuteStatement](https://docs.aws.amazon.com/goto/boto3/dynamodb-2012-08-10/ExecuteStatement)。
------
#### [ Ruby ]
**适用于 Ruby 的 SDK**
查看 GitHub，了解更多信息。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/ruby/example_code/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
使用 PartiQL 选择单个项目。
```
class DynamoDBPartiQLSingle
attr_reader :dynamo_resource, :table
def initialize(table_name)
client = Aws::DynamoDB::Client.new(region: 'us-east-1')
@dynamodb = Aws::DynamoDB::Resource.new(client: client)
@table = @dynamodb.table(table_name)
end
# Gets a single record from a table using PartiQL.
# Note: To perform more fine-grained selects,
# use the Client.query instance method instead.
#
# @param title [String] The title of the movie to search.
# @return [Aws::DynamoDB::Types::ExecuteStatementOutput]
def select_item_by_title(title)
request = {
statement: "SELECT * FROM \"#{@table.name}\" WHERE title=?",
parameters: [title]
}
@dynamodb.client.execute_statement(request)
end
```
使用 PartiQL 更新单个项目。
```
class DynamoDBPartiQLSingle
attr_reader :dynamo_resource, :table
def initialize(table_name)
client = Aws::DynamoDB::Client.new(region: 'us-east-1')
@dynamodb = Aws::DynamoDB::Resource.new(client: client)
@table = @dynamodb.table(table_name)
end
# Updates a single record from a table using PartiQL.
#
# @param title [String] The title of the movie to update.
# @param year [Integer] The year the movie was released.
# @param rating [Float] The new rating to assign the title.
# @return [Aws::DynamoDB::Types::ExecuteStatementOutput]
def update_rating_by_title(title, year, rating)
request = {
statement: "UPDATE \"#{@table.name}\" SET info.rating=? WHERE title=? and year=?",
parameters: [{ "N": rating }, title, year]
}
@dynamodb.client.execute_statement(request)
end
```
使用 PartiQL 添加单个项目。
```
class DynamoDBPartiQLSingle
attr_reader :dynamo_resource, :table
def initialize(table_name)
client = Aws::DynamoDB::Client.new(region: 'us-east-1')
@dynamodb = Aws::DynamoDB::Resource.new(client: client)
@table = @dynamodb.table(table_name)
end
# Adds a single record to a table using PartiQL.
#
# @param title [String] The title of the movie to update.
# @param year [Integer] The year the movie was released.
# @param plot [String] The plot of the movie.
# @param rating [Float] The new rating to assign the title.
# @return [Aws::DynamoDB::Types::ExecuteStatementOutput]
def insert_item(title, year, plot, rating)
request = {
statement: "INSERT INTO \"#{@table.name}\" VALUE {'title': ?, 'year': ?, 'info': ?}",
parameters: [title, year, { 'plot': plot, 'rating': rating }]
}
@dynamodb.client.execute_statement(request)
end
```
使用 PartiQL 删除单个项目。
```
class DynamoDBPartiQLSingle
attr_reader :dynamo_resource, :table
def initialize(table_name)
client = Aws::DynamoDB::Client.new(region: 'us-east-1')
@dynamodb = Aws::DynamoDB::Resource.new(client: client)
@table = @dynamodb.table(table_name)
end
# Deletes a single record from a table using PartiQL.
#
# @param title [String] The title of the movie to update.
# @param year [Integer] The year the movie was released.
# @return [Aws::DynamoDB::Types::ExecuteStatementOutput]
def delete_item_by_title(title, year)
request = {
statement: "DELETE FROM \"#{@table.name}\" WHERE title=? and year=?",
parameters: [title, year]
}
@dynamodb.client.execute_statement(request)
end
```
+ 有关 API 详细信息，请参阅《适用于 Ruby 的 AWS SDK API 参考》**中的 [ExecuteStatement](https://docs.aws.amazon.com/goto/SdkForRubyV3/dynamodb-2012-08-10/ExecuteStatement)。
------
有关 AWS SDK 开发人员指南和代码示例的完整列表，请参阅 [结合使用 DynamoDB 与 AWS SDK](sdk-general-information-section.md) 本主题还包括有关入门的信息以及有关先前的 SDK 版本的详细信息。
# 将 `GetItem` 与 AWS SDK 或 CLI 配合使用
以下代码示例演示如何使用 `GetItem`。
操作示例是大型程序的代码摘录，必须在上下文中运行。您可以在以下代码示例中查看此操作的上下文：
+ [了解基本功能](example_dynamodb_Scenario_GettingStartedMovies_section.md)
+ [借助 DAX 加快读取速度](example_dynamodb_Usage_DaxDemo_section.md)
+ [创建和管理 MRSC 全局表](example_dynamodb_Scenario_MRSCGlobalTables_section.md)
+ [使用全局表和多区域复制最终一致性（MREC）](example_dynamodb_Scenario_MultiRegionReplication_section.md)
------
#### [ .NET ]
**适用于 .NET 的 SDK (v4)**
查看 GitHub，了解更多信息。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/dotnetv4/DynamoDB#code-examples) 中查找完整示例，了解如何进行设置和运行。
```
///
/// Gets information about an existing movie from the table.
///
/// A Movie object containing information about
/// the movie to retrieve.
/// The name of the table containing the movie.
/// A Dictionary object containing information about the item
/// retrieved.
public async Task> GetItemAsync(Movie newMovie, string tableName)
{
try
{
var key = new Dictionary
{
["title"] = new AttributeValue { S = newMovie.Title },
["year"] = new AttributeValue { N = newMovie.Year.ToString() },
};
var request = new GetItemRequest
{
Key = key,
TableName = tableName,
};
var response = await _amazonDynamoDB.GetItemAsync(request);
return response.Item;
}
catch (ResourceNotFoundException ex)
{
Console.WriteLine($"Table {tableName} was not found. {ex.Message}");
return new Dictionary();
}
catch (AmazonDynamoDBException ex)
{
Console.WriteLine($"An Amazon DynamoDB error occurred while getting item. {ex.Message}");
throw;
}
catch (Exception ex)
{
Console.WriteLine($"An error occurred while getting item. {ex.Message}");
throw;
}
}
```
+ 有关 API 详细信息，请参阅《适用于 .NET 的 AWS SDK API Reference》**中的 [GetItem](https://docs.aws.amazon.com/goto/DotNetSDKV4/dynamodb-2012-08-10/GetItem)。
------
#### [ Bash ]
**AWS CLI 及 Bash 脚本**
查看 GitHub，了解更多信息。查找完整示例，了解如何在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/aws-cli/bash-linux/dynamodb#code-examples)中进行设置和运行。
```
#############################################################################
# function dynamodb_get_item
#
# This function gets an item from a DynamoDB table.
#
# Parameters:
# -n table_name -- The name of the table.
# -k keys -- Path to json file containing the keys that identify the item to get.
# [-q query] -- Optional JMESPath query expression.
#
# Returns:
# The item as text output.
# And:
# 0 - If successful.
# 1 - If it fails.
############################################################################
function dynamodb_get_item() {
local table_name keys query response
local option OPTARG # Required to use getopts command in a function.
# ######################################
# Function usage explanation
#######################################
function usage() {
echo "function dynamodb_get_item"
echo "Get an item from a DynamoDB table."
echo " -n table_name -- The name of the table."
echo " -k keys -- Path to json file containing the keys that identify the item to get."
echo " [-q query] -- Optional JMESPath query expression."
echo ""
}
query=""
while getopts "n:k:q:h" option; do
case "${option}" in
n) table_name="${OPTARG}" ;;
k) keys="${OPTARG}" ;;
q) query="${OPTARG}" ;;
h)
usage
return 0
;;
\?)
echo "Invalid parameter"
usage
return 1
;;
esac
done
export OPTIND=1
if [[ -z "$table_name" ]]; then
errecho "ERROR: You must provide a table name with the -n parameter."
usage
return 1
fi
if [[ -z "$keys" ]]; then
errecho "ERROR: You must provide a keys json file path the -k parameter."
usage
return 1
fi
if [[ -n "$query" ]]; then
response=$(aws dynamodb get-item \
--table-name "$table_name" \
--key file://"$keys" \
--output text \
--query "$query")
else
response=$(
aws dynamodb get-item \
--table-name "$table_name" \
--key file://"$keys" \
--output text
)
fi
local error_code=${?}
if [[ $error_code -ne 0 ]]; then
aws_cli_error_log $error_code
errecho "ERROR: AWS reports get-item operation failed.$response"
return 1
fi
if [[ -n "$query" ]]; then
echo "$response" | sed "/^\t/s/\t//1" # Remove initial tab that the JMSEPath query inserts on some strings.
else
echo "$response"
fi
return 0
}
```
本示例中使用的实用程序函数。
```
###############################################################################
# function errecho
#
# This function outputs everything sent to it to STDERR (standard error output).
###############################################################################
function errecho() {
printf "%s\n" "$*" 1>&2
}
##############################################################################
# function aws_cli_error_log()
#
# This function is used to log the error messages from the AWS CLI.
#
# See https://docs.aws.amazon.com/cli/latest/topic/return-codes.html#cli-aws-help-return-codes.
#
# The function expects the following argument:
# $1 - The error code returned by the AWS CLI.
#
# Returns:
# 0: - Success.
#
##############################################################################
function aws_cli_error_log() {
local err_code=$1
errecho "Error code : $err_code"
if [ "$err_code" == 1 ]; then
errecho " One or more S3 transfers failed."
elif [ "$err_code" == 2 ]; then
errecho " Command line failed to parse."
elif [ "$err_code" == 130 ]; then
errecho " Process received SIGINT."
elif [ "$err_code" == 252 ]; then
errecho " Command syntax invalid."
elif [ "$err_code" == 253 ]; then
errecho " The system environment or configuration was invalid."
elif [ "$err_code" == 254 ]; then
errecho " The service returned an error."
elif [ "$err_code" == 255 ]; then
errecho " 255 is a catch-all error."
fi
return 0
}
```
+ 有关 API 详细信息，请参阅《AWS CLI 命令参考》**中的 [GetItem](https://docs.aws.amazon.com/goto/aws-cli/dynamodb-2012-08-10/GetItem)。
------
#### [ C\$1\$1 ]
**SDK for C\$1\$1**
查看 GitHub，了解更多信息。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/cpp/example_code/dynamodb#code-examples) 中查找完整示例，了解如何进行设置和运行。
```
//! Get an item from an Amazon DynamoDB table.
/*!
\sa getItem()
\param tableName: The table name.
\param partitionKey: The partition key.
\param partitionValue: The value for the partition key.
\param clientConfiguration: AWS client configuration.
\return bool: Function succeeded.
*/
bool AwsDoc::DynamoDB::getItem(const Aws::String &tableName,
const Aws::String &partitionKey,
const Aws::String &partitionValue,
const Aws::Client::ClientConfiguration &clientConfiguration) {
Aws::DynamoDB::DynamoDBClient dynamoClient(clientConfiguration);
Aws::DynamoDB::Model::GetItemRequest request;
// Set up the request.
request.SetTableName(tableName);
request.AddKey(partitionKey,
Aws::DynamoDB::Model::AttributeValue().SetS(partitionValue));
// Retrieve the item's fields and values.
const Aws::DynamoDB::Model::GetItemOutcome &outcome = dynamoClient.GetItem(request);
if (outcome.IsSuccess()) {
// Reference the retrieved fields/values.
const Aws::Map &item = outcome.GetResult().GetItem();
if (!item.empty()) {
// Output each retrieved field and its value.
for (const auto &i: item)
std::cout << "Values: " << i.first << ": " << i.second.GetS()
<< std::endl;
}
else {
std::cout << "No item found with the key " << partitionKey << std::endl;
}
}
else {
std::cerr << "Failed to get item: " << outcome.GetError().GetMessage();
}
return outcome.IsSuccess();
}
```
+ 有关 API 详细信息，请参阅《适用于 C\$1\$1 的 AWS SDK API Reference》**中的 [GetItem](https://docs.aws.amazon.com/goto/SdkForCpp/dynamodb-2012-08-10/GetItem)。
------
#### [ CLI ]
**AWS CLI**
**示例 1：读取表中的项**
以下 `get-item` 示例将从 `MusicCollection` 表中检索项。该表具有 hash-and-range 主键（`Artist` 和 `SongTitle`），因此，您必须指定这两个属性。该命令还请求有关操作所用的读取容量的信息。
```
aws dynamodb get-item \
--table-name MusicCollection \
--key file://key.json \
--return-consumed-capacity TOTAL
```
的内容`key.json`：
```
{
"Artist": {"S": "Acme Band"},
"SongTitle": {"S": "Happy Day"}
}
```
输出：
```
{
"Item": {
"AlbumTitle": {
"S": "Songs About Life"
},
"SongTitle": {
"S": "Happy Day"
},
"Artist": {
"S": "Acme Band"
}
},
"ConsumedCapacity": {
"TableName": "MusicCollection",
"CapacityUnits": 0.5
}
}
```
有关更多信息，请参阅《Amazon DynamoDB 开发人员指南》**中的[读取项](https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/WorkingWithItems.html#WorkingWithItems.ReadingData)。
**示例 2：使用一致性读取来读取项**
以下示例使用强一致性读取从 `MusicCollection` 表中检索项。
```
aws dynamodb get-item \
--table-name MusicCollection \
--key file://key.json \
--consistent-read \
--return-consumed-capacity TOTAL
```
的内容`key.json`：
```
{
"Artist": {"S": "Acme Band"},
"SongTitle": {"S": "Happy Day"}
}
```
输出：
```
{
"Item": {
"AlbumTitle": {
"S": "Songs About Life"
},
"SongTitle": {
"S": "Happy Day"
},
"Artist": {
"S": "Acme Band"
}
},
"ConsumedCapacity": {
"TableName": "MusicCollection",
"CapacityUnits": 1.0
}
}
```
有关更多信息，请参阅《Amazon DynamoDB 开发人员指南》**中的[读取项](https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/WorkingWithItems.html#WorkingWithItems.ReadingData)。
**示例 3：检索项的特定属性**
以下示例使用投影表达式仅检索所需项的三个属性。
```
aws dynamodb get-item \
--table-name ProductCatalog \
--key '{"Id": {"N": "102"}}' \
--projection-expression "#T, #C, #P" \
--expression-attribute-names file://names.json
```
的内容`names.json`：
```
{
"#T": "Title",
"#C": "ProductCategory",
"#P": "Price"
}
```
输出：
```
{
"Item": {
"Price": {
"N": "20"
},
"Title": {
"S": "Book 102 Title"
},
"ProductCategory": {
"S": "Book"
}
}
}
```
有关更多信息，请参阅《Amazon DynamoDB 开发人员指南》**中的[读取项](https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/WorkingWithItems.html#WorkingWithItems.ReadingData)。
+ 有关 API 详细信息，请参阅《AWS CLI 命令参考》**中的 [GetItem](https://awscli.amazonaws.com/v2/documentation/api/latest/reference/dynamodb/get-item.html)。
------
#### [ Go ]
**适用于 Go 的 SDK V2**
查看 GitHub，了解更多信息。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/gov2/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
```
import (
"context"
"errors"
"log"
"time"
"github.com/aws/aws-sdk-go-v2/aws"
"github.com/aws/aws-sdk-go-v2/feature/dynamodb/attributevalue"
"github.com/aws/aws-sdk-go-v2/feature/dynamodb/expression"
"github.com/aws/aws-sdk-go-v2/service/dynamodb"
"github.com/aws/aws-sdk-go-v2/service/dynamodb/types"
)
// TableBasics encapsulates the Amazon DynamoDB service actions used in the examples.
// It contains a DynamoDB service client that is used to act on the specified table.
type TableBasics struct {
DynamoDbClient *dynamodb.Client
TableName string
}
// GetMovie gets movie data from the DynamoDB table by using the primary composite key
// made of title and year.
func (basics TableBasics) GetMovie(ctx context.Context, title string, year int) (Movie, error) {
movie := Movie{Title: title, Year: year}
response, err := basics.DynamoDbClient.GetItem(ctx, &dynamodb.GetItemInput{
Key: movie.GetKey(), TableName: aws.String(basics.TableName),
})
if err != nil {
log.Printf("Couldn't get info about %v. Here's why: %v\n", title, err)
} else {
err = attributevalue.UnmarshalMap(response.Item, &movie)
if err != nil {
log.Printf("Couldn't unmarshal response. Here's why: %v\n", err)
}
}
return movie, err
}
```
定义本示例中使用的 Movie 结构。
```
import (
"archive/zip"
"bytes"
"encoding/json"
"fmt"
"io"
"log"
"net/http"
"github.com/aws/aws-sdk-go-v2/feature/dynamodb/attributevalue"
"github.com/aws/aws-sdk-go-v2/service/dynamodb/types"
)
// Movie encapsulates data about a movie. Title and Year are the composite primary key
// of the movie in Amazon DynamoDB. Title is the sort key, Year is the partition key,
// and Info is additional data.
type Movie struct {
Title string `dynamodbav:"title"`
Year int `dynamodbav:"year"`
Info map[string]interface{} `dynamodbav:"info"`
}
// GetKey returns the composite primary key of the movie in a format that can be
// sent to DynamoDB.
func (movie Movie) GetKey() map[string]types.AttributeValue {
title, err := attributevalue.Marshal(movie.Title)
if err != nil {
panic(err)
}
year, err := attributevalue.Marshal(movie.Year)
if err != nil {
panic(err)
}
return map[string]types.AttributeValue{"title": title, "year": year}
}
// String returns the title, year, rating, and plot of a movie, formatted for the example.
func (movie Movie) String() string {
return fmt.Sprintf("%v\n\tReleased: %v\n\tRating: %v\n\tPlot: %v\n",
movie.Title, movie.Year, movie.Info["rating"], movie.Info["plot"])
}
```
+ 有关 API 详细信息，请参阅《适用于 Go 的 AWS SDK API Reference》**中的 [GetItem](https://pkg.go.dev/github.com/aws/aws-sdk-go-v2/service/dynamodb#Client.GetItem)。
------
#### [ Java ]
**适用于 Java 的 SDK 2.x**
查看 GitHub，了解更多信息。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javav2/example_code/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
使用 DynamoDbClient 从表中获取项目。
```
import software.amazon.awssdk.regions.Region;
import software.amazon.awssdk.services.dynamodb.model.DynamoDbException;
import software.amazon.awssdk.services.dynamodb.DynamoDbClient;
import software.amazon.awssdk.services.dynamodb.model.AttributeValue;
import software.amazon.awssdk.services.dynamodb.model.GetItemRequest;
import java.util.HashMap;
import java.util.Map;
import java.util.Set;
/**
* Before running this Java V2 code example, set up your development
* environment, including your credentials.
*
* For more information, see the following documentation topic:
*
* https://docs.aws.amazon.com/sdk-for-java/latest/developer-guide/get-started.html
*
* To get an item from an Amazon DynamoDB table using the AWS SDK for Java V2,
* its better practice to use the
* Enhanced Client, see the EnhancedGetItem example.
*/
public class GetItem {
public static void main(String[] args) {
final String usage = """
Usage:
Where:
tableName - The Amazon DynamoDB table from which an item is retrieved (for example, Music3).\s
key - The key used in the Amazon DynamoDB table (for example, Artist).\s
keyval - The key value that represents the item to get (for example, Famous Band).
""";
if (args.length != 3) {
System.out.println(usage);
System.exit(1);
}
String tableName = args[0];
String key = args[1];
String keyVal = args[2];
System.out.format("Retrieving item \"%s\" from \"%s\"\n", keyVal, tableName);
Region region = Region.US_EAST_1;
DynamoDbClient ddb = DynamoDbClient.builder()
.region(region)
.build();
getDynamoDBItem(ddb, tableName, key, keyVal);
ddb.close();
}
public static void getDynamoDBItem(DynamoDbClient ddb, String tableName, String key, String keyVal) {
HashMap keyToGet = new HashMap<>();
keyToGet.put(key, AttributeValue.builder()
.s(keyVal)
.build());
GetItemRequest request = GetItemRequest.builder()
.key(keyToGet)
.tableName(tableName)
.build();
try {
// If there is no matching item, GetItem does not return any data.
Map returnedItem = ddb.getItem(request).item();
if (returnedItem.isEmpty())
System.out.format("No item found with the key %s!\n", key);
else {
Set keys = returnedItem.keySet();
System.out.println("Amazon DynamoDB table attributes: \n");
for (String key1 : keys) {
System.out.format("%s: %s\n", key1, returnedItem.get(key1).toString());
}
}
} catch (DynamoDbException e) {
System.err.println(e.getMessage());
System.exit(1);
}
}
}
```
+ 有关 API 详细信息，请参阅《AWS SDK for Java 2.x API Reference》**中的 [GetItem](https://docs.aws.amazon.com/goto/SdkForJavaV2/dynamodb-2012-08-10/GetItem)。
------
#### [ JavaScript ]
**SDK for JavaScript (v3)**
查看 GitHub，了解更多信息。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javascriptv3/example_code/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
此示例使用文档客户端来简化在 DynamoDB 中处理项目的过程。有关 API 详细信息，请参阅 [GetCommand](https://docs.aws.amazon.com/AWSJavaScriptSDK/v3/latest/Package/-aws-sdk-lib-dynamodb/Class/GetCommand/)。
```
import { DynamoDBClient } from "@aws-sdk/client-dynamodb";
import { DynamoDBDocumentClient, GetCommand } from "@aws-sdk/lib-dynamodb";
const client = new DynamoDBClient({});
const docClient = DynamoDBDocumentClient.from(client);
export const main = async () => {
const command = new GetCommand({
TableName: "AngryAnimals",
Key: {
CommonName: "Shoebill",
},
});
const response = await docClient.send(command);
console.log(response);
return response;
};
```
+ 有关 API 详细信息，请参阅《适用于 JavaScript 的 AWS SDK API Reference》**中的 [GetItem](https://docs.aws.amazon.com/AWSJavaScriptSDK/v3/latest/client/dynamodb/command/GetItemCommand)。
**SDK for JavaScript (v2)**
查看 GitHub，了解更多信息。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javascript/example_code/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
从表中获取项目。
```
// Load the AWS SDK for Node.js
var AWS = require("aws-sdk");
// Set the region
AWS.config.update({ region: "REGION" });
// Create the DynamoDB service object
var ddb = new AWS.DynamoDB({ apiVersion: "2012-08-10" });
var params = {
TableName: "TABLE",
Key: {
KEY_NAME: { N: "001" },
},
ProjectionExpression: "ATTRIBUTE_NAME",
};
// Call DynamoDB to read the item from the table
ddb.getItem(params, function (err, data) {
if (err) {
console.log("Error", err);
} else {
console.log("Success", data.Item);
}
});
```
使用 DynamoDB 文档客户端从表中获取项目。
```
// Load the AWS SDK for Node.js
var AWS = require("aws-sdk");
// Set the region
AWS.config.update({ region: "REGION" });
// Create DynamoDB document client
var docClient = new AWS.DynamoDB.DocumentClient({ apiVersion: "2012-08-10" });
var params = {
TableName: "EPISODES_TABLE",
Key: { KEY_NAME: VALUE },
};
docClient.get(params, function (err, data) {
if (err) {
console.log("Error", err);
} else {
console.log("Success", data.Item);
}
});
```
+ 有关更多信息，请参阅《适用于 JavaScript 的 AWS SDK 开发人员指南》[https://docs.aws.amazon.com/sdk-for-javascript/v2/developer-guide/dynamodb-example-dynamodb-utilities.html#dynamodb-example-document-client-get](https://docs.aws.amazon.com/sdk-for-javascript/v2/developer-guide/dynamodb-example-dynamodb-utilities.html#dynamodb-example-document-client-get)。
+ 有关 API 详细信息，请参阅《适用于 JavaScript 的 AWS SDK API Reference》**中的 [GetItem](https://docs.aws.amazon.com/goto/AWSJavaScriptSDK/dynamodb-2012-08-10/GetItem)。
------
#### [ Kotlin ]
**SDK for Kotlin**
查看 GitHub，了解更多信息。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/kotlin/services/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
```
suspend fun getSpecificItem(
tableNameVal: String,
keyName: String,
keyVal: String,
) {
val keyToGet = mutableMapOf()
keyToGet[keyName] = AttributeValue.S(keyVal)
val request =
GetItemRequest {
key = keyToGet
tableName = tableNameVal
}
DynamoDbClient.fromEnvironment { region = "us-east-1" }.use { ddb ->
val returnedItem = ddb.getItem(request)
val numbersMap = returnedItem.item
numbersMap?.forEach { key1 ->
println(key1.key)
println(key1.value)
}
}
}
```
+ 有关 API 详细信息，请参阅《AWS SDK for Kotlin API Reference》**中的 [GetItem](https://sdk.amazonaws.com/kotlin/api/latest/index.html)。
------
#### [ PHP ]
**适用于 PHP 的 SDK**
查看 GitHub，了解更多信息。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/php/example_code/dynamodb#code-examples) 中查找完整示例，了解如何进行设置和运行。
```
$movie = $service->getItemByKey($tableName, $key);
echo "\nThe movie {$movie['Item']['title']['S']} was released in {$movie['Item']['year']['N']}.\n";
public function getItemByKey(string $tableName, array $key)
{
return $this->dynamoDbClient->getItem([
'Key' => $key['Item'],
'TableName' => $tableName,
]);
}
```
+ 有关 API 详细信息，请参阅《适用于 PHP 的 AWS SDK API Reference》**中的 [GetItem](https://docs.aws.amazon.com/goto/SdkForPHPV3/dynamodb-2012-08-10/GetItem)。
------
#### [ PowerShell ]
**适用于 PowerShell V4 的工具**
**示例 1：返回带有分区键 SongTitle 和排序键 Artist 的 DynamoDB 项目。**
```
$key = @{
SongTitle = 'Somewhere Down The Road'
Artist = 'No One You Know'
} | ConvertTo-DDBItem
Get-DDBItem -TableName 'Music' -Key $key | ConvertFrom-DDBItem
```
**输出：**
```
Name Value
---- -----
Genre Country
SongTitle Somewhere Down The Road
Price 1.94
Artist No One You Know
CriticRating 9
AlbumTitle Somewhat Famous
```
+ 有关 API 详细信息，请参阅《AWS Tools for PowerShell Cmdlet Reference (V4)》**中的 [GetItem](https://docs.aws.amazon.com/powershell/v4/reference)。
**适用于 PowerShell V5 的工具**
**示例 1：返回带有分区键 SongTitle 和排序键 Artist 的 DynamoDB 项目。**
```
$key = @{
SongTitle = 'Somewhere Down The Road'
Artist = 'No One You Know'
} | ConvertTo-DDBItem
Get-DDBItem -TableName 'Music' -Key $key | ConvertFrom-DDBItem
```
**输出：**
```
Name Value
---- -----
Genre Country
SongTitle Somewhere Down The Road
Price 1.94
Artist No One You Know
CriticRating 9
AlbumTitle Somewhat Famous
```
+ 有关 API 详细信息，请参阅《AWS Tools for PowerShell Cmdlet Reference (V5)》**中的 [GetItem](https://docs.aws.amazon.com/powershell/v5/reference)。
------
#### [ Python ]
**适用于 Python 的 SDK（Boto3）**
查看 GitHub，了解更多信息。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/python/example_code/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
```
class Movies:
"""Encapsulates an Amazon DynamoDB table of movie data.
Example data structure for a movie record in this table:
{
"year": 1999,
"title": "For Love of the Game",
"info": {
"directors": ["Sam Raimi"],
"release_date": "1999-09-15T00:00:00Z",
"rating": 6.3,
"plot": "A washed up pitcher flashes through his career.",
"rank": 4987,
"running_time_secs": 8220,
"actors": [
"Kevin Costner",
"Kelly Preston",
"John C. Reilly"
]
}
}
"""
def __init__(self, dyn_resource):
"""
:param dyn_resource: A Boto3 DynamoDB resource.
"""
self.dyn_resource = dyn_resource
# The table variable is set during the scenario in the call to
# 'exists' if the table exists. Otherwise, it is set by 'create_table'.
self.table = None
def get_movie(self, title, year):
"""
Gets movie data from the table for a specific movie.
:param title: The title of the movie.
:param year: The release year of the movie.
:return: The data about the requested movie.
"""
try:
response = self.table.get_item(Key={"year": year, "title": title})
except ClientError as err:
logger.error(
"Couldn't get movie %s from table %s. Here's why: %s: %s",
title,
self.table.name,
err.response["Error"]["Code"],
err.response["Error"]["Message"],
)
raise
else:
return response["Item"]
```
+ 有关 API 详细信息，请参阅《AWS SDK for Python (Boto3) API Reference》**中的 [GetItem](https://docs.aws.amazon.com/goto/boto3/dynamodb-2012-08-10/GetItem)。
------
#### [ Ruby ]
**适用于 Ruby 的 SDK**
查看 GitHub，了解更多信息。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/ruby/example_code/dynamodb#code-examples) 中查找完整示例，了解如何进行设置和运行。
```
class DynamoDBBasics
attr_reader :dynamo_resource, :table
def initialize(table_name)
client = Aws::DynamoDB::Client.new(region: 'us-east-1')
@dynamo_resource = Aws::DynamoDB::Resource.new(client: client)
@table = @dynamo_resource.table(table_name)
end
# Gets movie data from the table for a specific movie.
#
# @param title [String] The title of the movie.
# @param year [Integer] The release year of the movie.
# @return [Hash] The data about the requested movie.
def get_item(title, year)
@table.get_item(key: { 'year' => year, 'title' => title })
rescue Aws::DynamoDB::Errors::ServiceError => e
puts("Couldn't get movie #{title} (#{year}) from table #{@table.name}:\n")
puts("\t#{e.code}: #{e.message}")
raise
end
```
+ 有关 API 详细信息，请参阅《适用于 Ruby 的 AWS SDK API Reference》**中的 [GetItem](https://docs.aws.amazon.com/goto/SdkForRubyV3/dynamodb-2012-08-10/GetItem)。
------
#### [ SAP ABAP ]
**适用于 SAP ABAP 的 SDK**
查看 GitHub，了解更多信息。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/sap-abap/services/dyn#code-examples)中查找完整示例，了解如何进行设置和运行。
```
TRY.
oo_item = lo_dyn->getitem(
iv_tablename = iv_table_name
it_key = it_key ).
DATA(lt_attr) = oo_item->get_item( ).
DATA(lo_title) = lt_attr[ key = 'title' ]-value.
DATA(lo_year) = lt_attr[ key = 'year' ]-value.
DATA(lo_rating) = lt_attr[ key = 'rating' ]-value.
MESSAGE 'Movie name is: ' && lo_title->get_s( )
&& 'Movie year is: ' && lo_year->get_n( )
&& 'Moving rating is: ' && lo_rating->get_n( ) TYPE 'I'.
CATCH /aws1/cx_dynresourcenotfoundex.
MESSAGE 'The table or index does not exist' TYPE 'E'.
ENDTRY.
```
+ 有关 API 详细信息，请参阅《AWS SDK for SAP ABAP API Reference》**中的 [GetItem](https://docs.aws.amazon.com/sdk-for-sap-abap/v1/api/latest/index.html)。
------
#### [ Swift ]
**适用于 Swift 的 SDK**
查看 GitHub，了解更多信息。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/swift/example_code/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
```
import AWSDynamoDB
/// Return a `Movie` record describing the specified movie from the Amazon
/// DynamoDB table.
///
/// - Parameters:
/// - title: The movie's title (`String`).
/// - year: The movie's release year (`Int`).
///
/// - Throws: `MoviesError.ItemNotFound` if the movie isn't in the table.
///
/// - Returns: A `Movie` record with the movie's details.
func get(title: String, year: Int) async throws -> Movie {
do {
guard let client = self.ddbClient else {
throw MoviesError.UninitializedClient
}
let input = GetItemInput(
key: [
"year": .n(String(year)),
"title": .s(title)
],
tableName: self.tableName
)
let output = try await client.getItem(input: input)
guard let item = output.item else {
throw MoviesError.ItemNotFound
}
let movie = try Movie(withItem: item)
return movie
} catch {
print("ERROR: get:", dump(error))
throw error
}
}
```
+ 有关 API 详细信息，请参阅《AWS SDK for Swift API 参考》**中的 [GetItem](https://sdk.amazonaws.com/swift/api/awsdynamodb/latest/documentation/awsdynamodb/dynamodbclient/getitem(input:))。
------
有关 AWS SDK 开发人员指南和代码示例的完整列表，请参阅 [结合使用 DynamoDB 与 AWS SDK](sdk-general-information-section.md) 本主题还包括有关入门的信息以及有关先前的 SDK 版本的详细信息。
# 将 `ListTables` 与 AWS SDK 或 CLI 配合使用
以下代码示例演示如何使用 `ListTables`。
操作示例是大型程序的代码摘录，必须在上下文中运行。在以下代码示例中，您可以查看此操作的上下文：
+ [设置基于属性的访问控制](example_dynamodb_Scenario_ABACSetup_section.md)
------
#### [ .NET ]
**适用于 .NET 的 SDK**
查看 GitHub，了解更多信息。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/dotnetv3/dynamodb#code-examples) 中查找完整示例，了解如何进行设置和运行。
```
private static async Task ListMyTables()
{
Console.WriteLine("\n*** Listing tables ***");
string lastTableNameEvaluated = null;
do
{
var response = await Client.ListTablesAsync(new ListTablesRequest
{
Limit = 2,
ExclusiveStartTableName = lastTableNameEvaluated
});
foreach (var name in response.TableNames)
{
Console.WriteLine(name);
}
lastTableNameEvaluated = response.LastEvaluatedTableName;
} while (lastTableNameEvaluated != null);
}
```
+ 有关 API 详细信息，请参阅《适用于 .NET 的 AWS SDK API Reference》**中的 [ListTables](https://docs.aws.amazon.com/goto/DotNetSDKV3/dynamodb-2012-08-10/ListTables)。
------
#### [ Bash ]
**AWS CLI 及 Bash 脚本**
查看 GitHub，了解更多信息。查找完整示例，了解如何在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/aws-cli/bash-linux/dynamodb#code-examples)中进行设置和运行。
```
##############################################################################
# function dynamodb_list_tables
#
# This function lists all the tables in a DynamoDB.
#
# Returns:
# 0 - If successful.
# 1 - If it fails.
###########################################################################
function dynamodb_list_tables() {
response=$(aws dynamodb list-tables \
--output text \
--query "TableNames")
local error_code=${?}
if [[ $error_code -ne 0 ]]; then
aws_cli_error_log $error_code
errecho "ERROR: AWS reports batch-write-item operation failed.$response"
return 1
fi
echo "$response" | tr -s "[:space:]" "\n"
return 0
}
```
本示例中使用的实用程序函数。
```
###############################################################################
# function errecho
#
# This function outputs everything sent to it to STDERR (standard error output).
###############################################################################
function errecho() {
printf "%s\n" "$*" 1>&2
}
##############################################################################
# function aws_cli_error_log()
#
# This function is used to log the error messages from the AWS CLI.
#
# See https://docs.aws.amazon.com/cli/latest/topic/return-codes.html#cli-aws-help-return-codes.
#
# The function expects the following argument:
# $1 - The error code returned by the AWS CLI.
#
# Returns:
# 0: - Success.
#
##############################################################################
function aws_cli_error_log() {
local err_code=$1
errecho "Error code : $err_code"
if [ "$err_code" == 1 ]; then
errecho " One or more S3 transfers failed."
elif [ "$err_code" == 2 ]; then
errecho " Command line failed to parse."
elif [ "$err_code" == 130 ]; then
errecho " Process received SIGINT."
elif [ "$err_code" == 252 ]; then
errecho " Command syntax invalid."
elif [ "$err_code" == 253 ]; then
errecho " The system environment or configuration was invalid."
elif [ "$err_code" == 254 ]; then
errecho " The service returned an error."
elif [ "$err_code" == 255 ]; then
errecho " 255 is a catch-all error."
fi
return 0
}
```
+ 有关 API 详细信息，请参阅《AWS CLI 命令参考》**中的 [ListTables](https://docs.aws.amazon.com/goto/aws-cli/dynamodb-2012-08-10/ListTables)。
------
#### [ C\$1\$1 ]
**SDK for C\$1\$1**
查看 GitHub，了解更多信息。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/cpp/example_code/dynamodb#code-examples) 中查找完整示例，了解如何进行设置和运行。
```
//! List the Amazon DynamoDB tables for the current AWS account.
/*!
\sa listTables()
\param clientConfiguration: AWS client configuration.
\return bool: Function succeeded.
*/
bool AwsDoc::DynamoDB::listTables(
const Aws::Client::ClientConfiguration &clientConfiguration) {
Aws::DynamoDB::DynamoDBClient dynamoClient(clientConfiguration);
Aws::DynamoDB::Model::ListTablesRequest listTablesRequest;
listTablesRequest.SetLimit(50);
do {
const Aws::DynamoDB::Model::ListTablesOutcome &outcome = dynamoClient.ListTables(
listTablesRequest);
if (!outcome.IsSuccess()) {
std::cout << "Error: " << outcome.GetError().GetMessage() << std::endl;
return false;
}
for (const auto &tableName: outcome.GetResult().GetTableNames())
std::cout << tableName << std::endl;
listTablesRequest.SetExclusiveStartTableName(
outcome.GetResult().GetLastEvaluatedTableName());
} while (!listTablesRequest.GetExclusiveStartTableName().empty());
return true;
}
```
+ 有关 API 详细信息，请参阅《适用于 C\$1\$1 的 AWS SDK API Reference》**中的 [ListTables](https://docs.aws.amazon.com/goto/SdkForCpp/dynamodb-2012-08-10/ListTables)。
------
#### [ CLI ]
**AWS CLI**
**示例 1：列出表**
以下 `list-tables` 示例列出与当前 AWS 账户和区域关联的所有表。
```
aws dynamodb list-tables
```
输出：
```
{
"TableNames": [
"Forum",
"ProductCatalog",
"Reply",
"Thread"
]
}
```
有关更多信息，请参阅《Amazon DynamoDB 开发人员指南》**中的[列出表名称](https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/WorkingWithTables.Basics.html#WorkingWithTables.Basics.ListTables)。
**示例 2：限制页面大小**
以下示例返回所有现有表的列表，但在每次调用中仅检索一个项，必要时执行多次调用以获取整个列表。在对大量资源运行列表命令时，限制页面大小非常有用，使用默认页面大小 1000 时，可能会导致“超时”错误。
```
aws dynamodb list-tables \
--page-size 1
```
输出：
```
{
"TableNames": [
"Forum",
"ProductCatalog",
"Reply",
"Thread"
]
}
```
有关更多信息，请参阅《Amazon DynamoDB 开发人员指南》**中的[列出表名称](https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/WorkingWithTables.Basics.html#WorkingWithTables.Basics.ListTables)。
**示例 3：限制返回项的数量**
以下示例将返回项的数量限制为 2。响应包含用于检索下一页结果的 `NextToken` 值。
```
aws dynamodb list-tables \
--max-items 2
```
输出：
```
{
"TableNames": [
"Forum",
"ProductCatalog"
],
"NextToken": "abCDeFGhiJKlmnOPqrSTuvwxYZ1aBCdEFghijK7LM51nOpqRSTuv3WxY3ZabC5dEFGhI2Jk3LmnoPQ6RST9"
}
```
有关更多信息，请参阅《Amazon DynamoDB 开发人员指南》**中的[列出表名称](https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/WorkingWithTables.Basics.html#WorkingWithTables.Basics.ListTables)。
**示例 4：检索下一页结果**
以下命令将使用先前对 `list-tables` 命令的调用中的 `NextToken` 值来检索另一页结果。由于本例中的响应不包含 `NextToken` 值，因此，我们知道已经到达结果末尾。
```
aws dynamodb list-tables \
--starting-token abCDeFGhiJKlmnOPqrSTuvwxYZ1aBCdEFghijK7LM51nOpqRSTuv3WxY3ZabC5dEFGhI2Jk3LmnoPQ6RST9
```
输出：
```
{
"TableNames": [
"Reply",
"Thread"
]
}
```
有关更多信息，请参阅《Amazon DynamoDB 开发人员指南》**中的[列出表名称](https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/WorkingWithTables.Basics.html#WorkingWithTables.Basics.ListTables)。
+ 有关 API 详细信息，请参阅《AWS CLI 命令参考》**中的 [ListTables](https://awscli.amazonaws.com/v2/documentation/api/latest/reference/dynamodb/list-tables.html)。
------
#### [ Go ]
**适用于 Go 的 SDK V2**
查看 GitHub，了解更多信息。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/gov2/dynamodb#code-examples) 中查找完整示例，了解如何进行设置和运行。
```
import (
"context"
"errors"
"log"
"time"
"github.com/aws/aws-sdk-go-v2/aws"
"github.com/aws/aws-sdk-go-v2/feature/dynamodb/attributevalue"
"github.com/aws/aws-sdk-go-v2/feature/dynamodb/expression"
"github.com/aws/aws-sdk-go-v2/service/dynamodb"
"github.com/aws/aws-sdk-go-v2/service/dynamodb/types"
)
// TableBasics encapsulates the Amazon DynamoDB service actions used in the examples.
// It contains a DynamoDB service client that is used to act on the specified table.
type TableBasics struct {
DynamoDbClient *dynamodb.Client
TableName string
}
// ListTables lists the DynamoDB table names for the current account.
func (basics TableBasics) ListTables(ctx context.Context) ([]string, error) {
var tableNames []string
var output *dynamodb.ListTablesOutput
var err error
tablePaginator := dynamodb.NewListTablesPaginator(basics.DynamoDbClient, &dynamodb.ListTablesInput{})
for tablePaginator.HasMorePages() {
output, err = tablePaginator.NextPage(ctx)
if err != nil {
log.Printf("Couldn't list tables. Here's why: %v\n", err)
break
} else {
tableNames = append(tableNames, output.TableNames...)
}
}
return tableNames, err
}
```
+ 有关 API 详细信息，请参阅《适用于 Go 的 AWS SDK API Reference》**中的 [ListTables](https://pkg.go.dev/github.com/aws/aws-sdk-go-v2/service/dynamodb#Client.ListTables)。
------
#### [ Java ]
**适用于 Java 的 SDK 2.x**
查看 GitHub，了解更多信息。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javav2/example_code/dynamodb#code-examples) 中查找完整示例，了解如何进行设置和运行。
```
import software.amazon.awssdk.regions.Region;
import software.amazon.awssdk.services.dynamodb.DynamoDbClient;
import software.amazon.awssdk.services.dynamodb.model.DynamoDbException;
import software.amazon.awssdk.services.dynamodb.model.ListTablesRequest;
import software.amazon.awssdk.services.dynamodb.model.ListTablesResponse;
import java.util.List;
/**
* Before running this Java V2 code example, set up your development
* environment, including your credentials.
*
* For more information, see the following documentation topic:
*
* https://docs.aws.amazon.com/sdk-for-java/latest/developer-guide/get-started.html
*/
public class ListTables {
public static void main(String[] args) {
System.out.println("Listing your Amazon DynamoDB tables:\n");
Region region = Region.US_EAST_1;
DynamoDbClient ddb = DynamoDbClient.builder()
.region(region)
.build();
listAllTables(ddb);
ddb.close();
}
public static void listAllTables(DynamoDbClient ddb) {
boolean moreTables = true;
String lastName = null;
while (moreTables) {
try {
ListTablesResponse response = null;
if (lastName == null) {
ListTablesRequest request = ListTablesRequest.builder().build();
response = ddb.listTables(request);
} else {
ListTablesRequest request = ListTablesRequest.builder()
.exclusiveStartTableName(lastName).build();
response = ddb.listTables(request);
}
List tableNames = response.tableNames();
if (tableNames.size() > 0) {
for (String curName : tableNames) {
System.out.format("* %s\n", curName);
}
} else {
System.out.println("No tables found!");
System.exit(0);
}
lastName = response.lastEvaluatedTableName();
if (lastName == null) {
moreTables = false;
}
} catch (DynamoDbException e) {
System.err.println(e.getMessage());
System.exit(1);
}
}
System.out.println("\nDone!");
}
}
```
+ 有关 API 详细信息，请参阅《AWS SDK for Java 2.x API Reference》**中的 [ListTables](https://docs.aws.amazon.com/goto/SdkForJavaV2/dynamodb-2012-08-10/ListTables)。
------
#### [ JavaScript ]
**适用于 JavaScript 的 SDK（v3）**
查看 GitHub，了解更多信息。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javascriptv3/example_code/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
```
import { ListTablesCommand, DynamoDBClient } from "@aws-sdk/client-dynamodb";
const client = new DynamoDBClient({});
export const main = async () => {
const command = new ListTablesCommand({});
const response = await client.send(command);
console.log(response);
return response;
};
```
+ 有关更多信息，请参阅《适用于 JavaScript 的 AWS SDK 开发人员指南》[https://docs.aws.amazon.com/sdk-for-javascript/v3/developer-guide/dynamodb-examples-using-tables.html#dynamodb-examples-using-tables-listing-tables](https://docs.aws.amazon.com/sdk-for-javascript/v3/developer-guide/dynamodb-examples-using-tables.html#dynamodb-examples-using-tables-listing-tables)。
+ 有关 API 详细信息，请参阅《适用于 JavaScript 的 AWS SDK API Reference》**中的 [ListTables](https://docs.aws.amazon.com/AWSJavaScriptSDK/v3/latest/client/dynamodb/command/ListTablesCommand)。
**SDK for JavaScript (v2)**
查看 GitHub，了解更多信息。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javascript/example_code/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
```
// Load the AWS SDK for Node.js
var AWS = require("aws-sdk");
// Set the region
AWS.config.update({ region: "REGION" });
// Create the DynamoDB service object
var ddb = new AWS.DynamoDB({ apiVersion: "2012-08-10" });
// Call DynamoDB to retrieve the list of tables
ddb.listTables({ Limit: 10 }, function (err, data) {
if (err) {
console.log("Error", err.code);
} else {
console.log("Table names are ", data.TableNames);
}
});
```
+ 有关更多信息，请参阅《适用于 JavaScript 的 AWS SDK 开发人员指南》[https://docs.aws.amazon.com/sdk-for-javascript/v2/developer-guide/dynamodb-examples-using-tables.html#dynamodb-examples-using-tables-listing-tables](https://docs.aws.amazon.com/sdk-for-javascript/v2/developer-guide/dynamodb-examples-using-tables.html#dynamodb-examples-using-tables-listing-tables)。
+ 有关 API 详细信息，请参阅《适用于 JavaScript 的 AWS SDK API Reference》**中的 [ListTables](https://docs.aws.amazon.com/goto/AWSJavaScriptSDK/dynamodb-2012-08-10/ListTables)。
------
#### [ Kotlin ]
**SDK for Kotlin**
查看 GitHub，了解更多信息。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/kotlin/services/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
```
suspend fun listAllTables() {
DynamoDbClient.fromEnvironment { region = "us-east-1" }.use { ddb ->
val response = ddb.listTables(ListTablesRequest {})
response.tableNames?.forEach { tableName ->
println("Table name is $tableName")
}
}
}
```
+ 有关 API 详细信息，请参阅《AWS SDK for Kotlin API Reference》**中的 [ListTables](https://sdk.amazonaws.com/kotlin/api/latest/index.html)。
------
#### [ PHP ]
**适用于 PHP 的 SDK**
查看 GitHub，了解更多信息。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/php/example_code/dynamodb#code-examples) 中查找完整示例，了解如何进行设置和运行。
```
public function listTables($exclusiveStartTableName = "", $limit = 100)
{
$this->dynamoDbClient->listTables([
'ExclusiveStartTableName' => $exclusiveStartTableName,
'Limit' => $limit,
]);
}
```
+ 有关 API 详细信息，请参阅《适用于 PHP 的 AWS SDK API Reference》**中的 [ListTables](https://docs.aws.amazon.com/goto/SdkForPHPV3/dynamodb-2012-08-10/ListTables)。
------
#### [ PowerShell ]
**适用于 PowerShell V4 的工具**
**示例 1：返回所有表的详细信息，自动迭代，直到服务指示不存在其它表。**
```
Get-DDBTableList
```
+ 有关 API 详细信息，请参阅《AWS Tools for PowerShell Cmdlet Reference (V4)》**中的 [ListTables](https://docs.aws.amazon.com/powershell/v4/reference)。
**适用于 PowerShell V5 的工具**
**示例 1：返回所有表的详细信息，自动迭代，直到服务指示不存在其它表。**
```
Get-DDBTableList
```
+ 有关 API 详细信息，请参阅《AWS Tools for PowerShell Cmdlet Reference (V5)》**中的 [ListTables](https://docs.aws.amazon.com/powershell/v5/reference)。
------
#### [ Python ]
**适用于 Python 的 SDK（Boto3）**
查看 GitHub，了解更多信息。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/python/example_code/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
```
class Movies:
"""Encapsulates an Amazon DynamoDB table of movie data.
Example data structure for a movie record in this table:
{
"year": 1999,
"title": "For Love of the Game",
"info": {
"directors": ["Sam Raimi"],
"release_date": "1999-09-15T00:00:00Z",
"rating": 6.3,
"plot": "A washed up pitcher flashes through his career.",
"rank": 4987,
"running_time_secs": 8220,
"actors": [
"Kevin Costner",
"Kelly Preston",
"John C. Reilly"
]
}
}
"""
def __init__(self, dyn_resource):
"""
:param dyn_resource: A Boto3 DynamoDB resource.
"""
self.dyn_resource = dyn_resource
# The table variable is set during the scenario in the call to
# 'exists' if the table exists. Otherwise, it is set by 'create_table'.
self.table = None
def list_tables(self):
"""
Lists the Amazon DynamoDB tables for the current account.
:return: The list of tables.
"""
try:
tables = []
for table in self.dyn_resource.tables.all():
print(table.name)
tables.append(table)
except ClientError as err:
logger.error(
"Couldn't list tables. Here's why: %s: %s",
err.response["Error"]["Code"],
err.response["Error"]["Message"],
)
raise
else:
return tables
```
+ 有关 API 详细信息，请参阅《AWS SDK for Python (Boto3) API Reference》**中的 [ListTables](https://docs.aws.amazon.com/goto/boto3/dynamodb-2012-08-10/ListTables)。
------
#### [ Ruby ]
**适用于 Ruby 的 SDK**
查看 GitHub，了解更多信息。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/python/example_code/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
确定表是否存在。
```
# Encapsulates an Amazon DynamoDB table of movie data.
class Scaffold
attr_reader :dynamo_resource, :table_name, :table
def initialize(table_name)
client = Aws::DynamoDB::Client.new(region: 'us-east-1')
@dynamo_resource = Aws::DynamoDB::Resource.new(client: client)
@table_name = table_name
@table = nil
@logger = Logger.new($stdout)
@logger.level = Logger::DEBUG
end
# Determines whether a table exists. As a side effect, stores the table in
# a member variable.
#
# @param table_name [String] The name of the table to check.
# @return [Boolean] True when the table exists; otherwise, False.
def exists?(table_name)
@dynamo_resource.client.describe_table(table_name: table_name)
@logger.debug("Table #{table_name} exists")
rescue Aws::DynamoDB::Errors::ResourceNotFoundException
@logger.debug("Table #{table_name} doesn't exist")
false
rescue Aws::DynamoDB::Errors::ServiceError => e
puts("Couldn't check for existence of #{table_name}:\n")
puts("\t#{e.code}: #{e.message}")
raise
end
```
+ 有关 API 详细信息，请参阅《适用于 Ruby 的 AWS SDK API Reference》**中的 [ListTables](https://docs.aws.amazon.com/goto/SdkForRubyV3/dynamodb-2012-08-10/ListTables)。
------
#### [ Rust ]
**适用于 Rust 的 SDK**
查看 GitHub，了解更多信息。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/rustv1/examples/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
```
pub async fn list_tables(client: &Client) -> Result, Error> {
let paginator = client.list_tables().into_paginator().items().send();
let table_names = paginator.collect::, _>>().await?;
println!("Tables:");
for name in &table_names {
println!(" {}", name);
}
println!("Found {} tables", table_names.len());
Ok(table_names)
}
```
确定表是否存在。
```
pub async fn table_exists(client: &Client, table: &str) -> Result {
debug!("Checking for table: {table}");
let table_list = client.list_tables().send().await;
match table_list {
Ok(list) => Ok(list.table_names().contains(&table.into())),
Err(e) => Err(e.into()),
}
}
```
+ 有关 API 详细信息，请参阅《AWS SDK for Rust API Reference》**中的 [ListTables](https://docs.rs/aws-sdk-dynamodb/latest/aws_sdk_dynamodb/client/struct.Client.html#method.list_tables)。
------
#### [ SAP ABAP ]
**适用于 SAP ABAP 的 SDK**
查看 GitHub，了解更多信息。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/sap-abap/services/dyn#code-examples)中查找完整示例，了解如何进行设置和运行。
```
TRY.
oo_result = lo_dyn->listtables( ).
" You can loop over the oo_result to get table properties like this.
LOOP AT oo_result->get_tablenames( ) INTO DATA(lo_table_name).
DATA(lv_tablename) = lo_table_name->get_value( ).
ENDLOOP.
DATA(lv_tablecount) = lines( oo_result->get_tablenames( ) ).
MESSAGE 'Found ' && lv_tablecount && ' tables' TYPE 'I'.
CATCH /aws1/cx_rt_service_generic INTO DATA(lo_exception).
DATA(lv_error) = |"{ lo_exception->av_err_code }" - { lo_exception->av_err_msg }|.
MESSAGE lv_error TYPE 'E'.
ENDTRY.
```
+ 有关 API 详细信息，请参阅《AWS SDK for SAP ABAP API Reference》**中的 [ListTables](https://docs.aws.amazon.com/sdk-for-sap-abap/v1/api/latest/index.html)。
------
#### [ Swift ]
**适用于 Swift 的 SDK**
查看 GitHub，了解更多信息。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/swift/example_code/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
```
import AWSDynamoDB
/// Get a list of the DynamoDB tables available in the specified Region.
///
/// - Returns: An array of strings listing all of the tables available
/// in the Region specified when the session was created.
public func getTableList() async throws -> [String] {
let input = ListTablesInput(
)
return try await session.listTables(input: input)
}
```
+ 有关 API 详细信息，请参阅《AWS SDK for Swift API 参考》**中的 [ListTables](https://sdk.amazonaws.com/swift/api/awsdynamodb/latest/documentation/awsdynamodb/dynamodbclient/listtables(input:))。
------
有关 AWS SDK 开发人员指南和代码示例的完整列表，请参阅 [结合使用 DynamoDB 与 AWS SDK](sdk-general-information-section.md) 本主题还包括有关入门的信息以及有关先前的 SDK 版本的详细信息。
# 将 `PutItem` 与 AWS SDK 或 CLI 配合使用
以下代码示例演示如何使用 `PutItem`。
操作示例是大型程序的代码摘录，必须在上下文中运行。您可以在以下代码示例中查看此操作的上下文：
+ [了解基本功能](example_dynamodb_Scenario_GettingStartedMovies_section.md)
+ [借助 DAX 加快读取速度](example_dynamodb_Usage_DaxDemo_section.md)
+ [高级全局二级索引方案](example_dynamodb_Scenario_GSIAdvanced_section.md)
+ [创建设置了 TTL 的项目](example_dynamodb_PutItemTTL_section.md)
+ [创建和管理用于演示 MREC 的全局表](example_dynamodb_Scenario_GlobalTableOperations_section.md)
+ [创建和管理 MRSC 全局表](example_dynamodb_Scenario_MRSCGlobalTables_section.md)
+ [使用条件运算](example_dynamodb_Scenario_ConditionalOperations_section.md)
+ [使用全局表和多区域复制最终一致性（MREC）](example_dynamodb_Scenario_MultiRegionReplication_section.md)
+ [处理 Streams 和生存时间](example_dynamodb_Scenario_StreamsAndTTL_section.md)
------
#### [ .NET ]
**适用于 .NET 的 SDK (v4)**
查看 GitHub，了解更多信息。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/dotnetv4/DynamoDB#code-examples) 中查找完整示例，了解如何进行设置和运行。
```
///
/// Adds a new item to the table.
///
/// A Movie object containing informtation for
/// the movie to add to the table.
/// The name of the table where the item will be added.
/// A Boolean value that indicates the results of adding the item.
public async Task PutItemAsync(Movie newMovie, string tableName)
{
try
{
var item = new Dictionary
{
["title"] = new AttributeValue { S = newMovie.Title },
["year"] = new AttributeValue { N = newMovie.Year.ToString() },
};
var request = new PutItemRequest
{
TableName = tableName,
Item = item,
};
await _amazonDynamoDB.PutItemAsync(request);
return true;
}
catch (ResourceNotFoundException ex)
{
Console.WriteLine($"Table {tableName} was not found. {ex.Message}");
return false;
}
catch (AmazonDynamoDBException ex)
{
Console.WriteLine($"An Amazon DynamoDB error occurred while putting item. {ex.Message}");
throw;
}
catch (Exception ex)
{
Console.WriteLine($"An error occurred while putting item. {ex.Message}");
throw;
}
}
```
+ 有关 API 详细信息，请参阅《适用于 .NET 的 AWS SDK API Reference》**中的 [PutItem](https://docs.aws.amazon.com/goto/DotNetSDKV4/dynamodb-2012-08-10/PutItem)。
------
#### [ Bash ]
**AWS CLI 及 Bash 脚本**
查看 GitHub，了解更多信息。查找完整示例，了解如何在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/aws-cli/bash-linux/dynamodb#code-examples)中进行设置和运行。
```
##############################################################################
# function dynamodb_put_item
#
# This function puts an item into a DynamoDB table.
#
# Parameters:
# -n table_name -- The name of the table.
# -i item -- Path to json file containing the item values.
#
# Returns:
# 0 - If successful.
# 1 - If it fails.
##############################################################################
function dynamodb_put_item() {
local table_name item response
local option OPTARG # Required to use getopts command in a function.
#######################################
# Function usage explanation
#######################################
function usage() {
echo "function dynamodb_put_item"
echo "Put an item into a DynamoDB table."
echo " -n table_name -- The name of the table."
echo " -i item -- Path to json file containing the item values."
echo ""
}
while getopts "n:i:h" option; do
case "${option}" in
n) table_name="${OPTARG}" ;;
i) item="${OPTARG}" ;;
h)
usage
return 0
;;
\?)
echo "Invalid parameter"
usage
return 1
;;
esac
done
export OPTIND=1
if [[ -z "$table_name" ]]; then
errecho "ERROR: You must provide a table name with the -n parameter."
usage
return 1
fi
if [[ -z "$item" ]]; then
errecho "ERROR: You must provide an item with the -i parameter."
usage
return 1
fi
iecho "Parameters:\n"
iecho " table_name: $table_name"
iecho " item: $item"
iecho ""
iecho ""
response=$(aws dynamodb put-item \
--table-name "$table_name" \
--item file://"$item")
local error_code=${?}
if [[ $error_code -ne 0 ]]; then
aws_cli_error_log $error_code
errecho "ERROR: AWS reports put-item operation failed.$response"
return 1
fi
return 0
}
```
本示例中使用的实用程序函数。
```
###############################################################################
# function iecho
#
# This function enables the script to display the specified text only if
# the global variable $VERBOSE is set to true.
###############################################################################
function iecho() {
if [[ $VERBOSE == true ]]; then
echo "$@"
fi
}
###############################################################################
# function errecho
#
# This function outputs everything sent to it to STDERR (standard error output).
###############################################################################
function errecho() {
printf "%s\n" "$*" 1>&2
}
##############################################################################
# function aws_cli_error_log()
#
# This function is used to log the error messages from the AWS CLI.
#
# See https://docs.aws.amazon.com/cli/latest/topic/return-codes.html#cli-aws-help-return-codes.
#
# The function expects the following argument:
# $1 - The error code returned by the AWS CLI.
#
# Returns:
# 0: - Success.
#
##############################################################################
function aws_cli_error_log() {
local err_code=$1
errecho "Error code : $err_code"
if [ "$err_code" == 1 ]; then
errecho " One or more S3 transfers failed."
elif [ "$err_code" == 2 ]; then
errecho " Command line failed to parse."
elif [ "$err_code" == 130 ]; then
errecho " Process received SIGINT."
elif [ "$err_code" == 252 ]; then
errecho " Command syntax invalid."
elif [ "$err_code" == 253 ]; then
errecho " The system environment or configuration was invalid."
elif [ "$err_code" == 254 ]; then
errecho " The service returned an error."
elif [ "$err_code" == 255 ]; then
errecho " 255 is a catch-all error."
fi
return 0
}
```
+ 有关 API 详细信息，请参阅《AWS CLI 命令参考》**中的 [PutItem](https://docs.aws.amazon.com/goto/aws-cli/dynamodb-2012-08-10/PutItem)。
------
#### [ C\$1\$1 ]
**SDK for C\$1\$1**
查看 GitHub，了解更多信息。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/cpp/example_code/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
```
//! Put an item in an Amazon DynamoDB table.
/*!
\sa putItem()
\param tableName: The table name.
\param artistKey: The artist key. This is the partition key for the table.
\param artistValue: The artist value.
\param albumTitleKey: The album title key.
\param albumTitleValue: The album title value.
\param awardsKey: The awards key.
\param awardsValue: The awards value.
\param songTitleKey: The song title key.
\param songTitleValue: The song title value.
\param clientConfiguration: AWS client configuration.
\return bool: Function succeeded.
*/
bool AwsDoc::DynamoDB::putItem(const Aws::String &tableName,
const Aws::String &artistKey,
const Aws::String &artistValue,
const Aws::String &albumTitleKey,
const Aws::String &albumTitleValue,
const Aws::String &awardsKey,
const Aws::String &awardsValue,
const Aws::String &songTitleKey,
const Aws::String &songTitleValue,
const Aws::Client::ClientConfiguration &clientConfiguration) {
Aws::DynamoDB::DynamoDBClient dynamoClient(clientConfiguration);
Aws::DynamoDB::Model::PutItemRequest putItemRequest;
putItemRequest.SetTableName(tableName);
putItemRequest.AddItem(artistKey, Aws::DynamoDB::Model::AttributeValue().SetS(
artistValue)); // This is the hash key.
putItemRequest.AddItem(albumTitleKey, Aws::DynamoDB::Model::AttributeValue().SetS(
albumTitleValue));
putItemRequest.AddItem(awardsKey,
Aws::DynamoDB::Model::AttributeValue().SetS(awardsValue));
putItemRequest.AddItem(songTitleKey,
Aws::DynamoDB::Model::AttributeValue().SetS(songTitleValue));
const Aws::DynamoDB::Model::PutItemOutcome outcome = dynamoClient.PutItem(
putItemRequest);
if (outcome.IsSuccess()) {
std::cout << "Successfully added Item!" << std::endl;
}
else {
std::cerr << outcome.GetError().GetMessage() << std::endl;
return false;
}
return waitTableActive(tableName, dynamoClient);
}
```
等待表变为活动状态的代码。
```
//! Query a newly created DynamoDB table until it is active.
/*!
\sa waitTableActive()
\param waitTableActive: The DynamoDB table's name.
\param dynamoClient: A DynamoDB client.
\return bool: Function succeeded.
*/
bool AwsDoc::DynamoDB::waitTableActive(const Aws::String &tableName,
const Aws::DynamoDB::DynamoDBClient &dynamoClient) {
// Repeatedly call DescribeTable until table is ACTIVE.
const int MAX_QUERIES = 20;
Aws::DynamoDB::Model::DescribeTableRequest request;
request.SetTableName(tableName);
int count = 0;
while (count < MAX_QUERIES) {
const Aws::DynamoDB::Model::DescribeTableOutcome &result = dynamoClient.DescribeTable(
request);
if (result.IsSuccess()) {
Aws::DynamoDB::Model::TableStatus status = result.GetResult().GetTable().GetTableStatus();
if (Aws::DynamoDB::Model::TableStatus::ACTIVE != status) {
std::this_thread::sleep_for(std::chrono::seconds(1));
}
else {
return true;
}
}
else {
std::cerr << "Error DynamoDB::waitTableActive "
<< result.GetError().GetMessage() << std::endl;
return false;
}
count++;
}
return false;
}
```
+ 有关 API 详细信息，请参阅《适用于 C\$1\$1 的 AWS SDK API Reference》**中的 [PutItem](https://docs.aws.amazon.com/goto/SdkForCpp/dynamodb-2012-08-10/PutItem)。
------
#### [ CLI ]
**AWS CLI**
**示例 1：向表中添加项**
以下 `put-item` 示例将新项添加到 *MusicCollection* 表中。
```
aws dynamodb put-item \
--table-name MusicCollection \
--item file://item.json \
--return-consumed-capacity TOTAL \
--return-item-collection-metrics SIZE
```
的内容`item.json`：
```
{
"Artist": {"S": "No One You Know"},
"SongTitle": {"S": "Call Me Today"},
"AlbumTitle": {"S": "Greatest Hits"}
}
```
输出：
```
{
"ConsumedCapacity": {
"TableName": "MusicCollection",
"CapacityUnits": 1.0
},
"ItemCollectionMetrics": {
"ItemCollectionKey": {
"Artist": {
"S": "No One You Know"
}
},
"SizeEstimateRangeGB": [
0.0,
1.0
]
}
}
```
有关更多信息，请参阅《Amazon DynamoDB 开发人员指南》**中的[写入项](https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/WorkingWithItems.html#WorkingWithItems.WritingData)。
**示例 2：有条件地覆盖表中的项**
仅当 `MusicCollection` 表中的现有项具有值为 `Greatest Hits` 的 `AlbumTitle` 属性时，以下 `put-item` 示例才会覆盖该项。该命令将返回该项先前的值。
```
aws dynamodb put-item \
--table-name MusicCollection \
--item file://item.json \
--condition-expression "#A = :A" \
--expression-attribute-names file://names.json \
--expression-attribute-values file://values.json \
--return-values ALL_OLD
```
的内容`item.json`：
```
{
"Artist": {"S": "No One You Know"},
"SongTitle": {"S": "Call Me Today"},
"AlbumTitle": {"S": "Somewhat Famous"}
}
```
的内容`names.json`：
```
{
"#A": "AlbumTitle"
}
```
的内容`values.json`：
```
{
":A": {"S": "Greatest Hits"}
}
```
输出：
```
{
"Attributes": {
"AlbumTitle": {
"S": "Greatest Hits"
},
"Artist": {
"S": "No One You Know"
},
"SongTitle": {
"S": "Call Me Today"
}
}
}
```
如果键已存在，您应看到以下输出：
```
A client error (ConditionalCheckFailedException) occurred when calling the PutItem operation: The conditional request failed.
```
有关更多信息，请参阅《Amazon DynamoDB 开发人员指南》**中的[写入项](https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/WorkingWithItems.html#WorkingWithItems.WritingData)。
+ 有关 API 详细信息，请参阅《AWS CLI 命令参考》**中的 [PutItem](https://awscli.amazonaws.com/v2/documentation/api/latest/reference/dynamodb/put-item.html)。
------
#### [ Go ]
**适用于 Go 的 SDK V2**
查看 GitHub，了解更多信息。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/gov2/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
```
import (
"context"
"errors"
"log"
"time"
"github.com/aws/aws-sdk-go-v2/aws"
"github.com/aws/aws-sdk-go-v2/feature/dynamodb/attributevalue"
"github.com/aws/aws-sdk-go-v2/feature/dynamodb/expression"
"github.com/aws/aws-sdk-go-v2/service/dynamodb"
"github.com/aws/aws-sdk-go-v2/service/dynamodb/types"
)
// TableBasics encapsulates the Amazon DynamoDB service actions used in the examples.
// It contains a DynamoDB service client that is used to act on the specified table.
type TableBasics struct {
DynamoDbClient *dynamodb.Client
TableName string
}
// AddMovie adds a movie the DynamoDB table.
func (basics TableBasics) AddMovie(ctx context.Context, movie Movie) error {
item, err := attributevalue.MarshalMap(movie)
if err != nil {
panic(err)
}
_, err = basics.DynamoDbClient.PutItem(ctx, &dynamodb.PutItemInput{
TableName: aws.String(basics.TableName), Item: item,
})
if err != nil {
log.Printf("Couldn't add item to table. Here's why: %v\n", err)
}
return err
}
```
定义本示例中使用的 Movie 结构。
```
import (
"archive/zip"
"bytes"
"encoding/json"
"fmt"
"io"
"log"
"net/http"
"github.com/aws/aws-sdk-go-v2/feature/dynamodb/attributevalue"
"github.com/aws/aws-sdk-go-v2/service/dynamodb/types"
)
// Movie encapsulates data about a movie. Title and Year are the composite primary key
// of the movie in Amazon DynamoDB. Title is the sort key, Year is the partition key,
// and Info is additional data.
type Movie struct {
Title string `dynamodbav:"title"`
Year int `dynamodbav:"year"`
Info map[string]interface{} `dynamodbav:"info"`
}
// GetKey returns the composite primary key of the movie in a format that can be
// sent to DynamoDB.
func (movie Movie) GetKey() map[string]types.AttributeValue {
title, err := attributevalue.Marshal(movie.Title)
if err != nil {
panic(err)
}
year, err := attributevalue.Marshal(movie.Year)
if err != nil {
panic(err)
}
return map[string]types.AttributeValue{"title": title, "year": year}
}
// String returns the title, year, rating, and plot of a movie, formatted for the example.
func (movie Movie) String() string {
return fmt.Sprintf("%v\n\tReleased: %v\n\tRating: %v\n\tPlot: %v\n",
movie.Title, movie.Year, movie.Info["rating"], movie.Info["plot"])
}
```
+ 有关 API 详细信息，请参阅《适用于 Go 的 AWS SDK API Reference》**中的 [PutItem](https://pkg.go.dev/github.com/aws/aws-sdk-go-v2/service/dynamodb#Client.PutItem)。
------
#### [ Java ]
**适用于 Java 的 SDK 2.x**
查看 GitHub，了解更多信息。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javav2/example_code/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
使用 [DynamoDbClient](https://docs.aws.amazon.com/sdk-for-java/latest/reference/software/amazon/awssdk/services/dynamodb/DynamoDbClient.html) 将项目放入表中。
```
import software.amazon.awssdk.regions.Region;
import software.amazon.awssdk.services.dynamodb.DynamoDbClient;
import software.amazon.awssdk.services.dynamodb.model.AttributeValue;
import software.amazon.awssdk.services.dynamodb.model.DynamoDbException;
import software.amazon.awssdk.services.dynamodb.model.PutItemRequest;
import software.amazon.awssdk.services.dynamodb.model.PutItemResponse;
import software.amazon.awssdk.services.dynamodb.model.ResourceNotFoundException;
import java.util.HashMap;
/**
* Before running this Java V2 code example, set up your development
* environment, including your credentials.
*
* For more information, see the following documentation topic:
*
* https://docs.aws.amazon.com/sdk-for-java/latest/developer-guide/get-started.html
*
* To place items into an Amazon DynamoDB table using the AWS SDK for Java V2,
* its better practice to use the
* Enhanced Client. See the EnhancedPutItem example.
*/
public class PutItem {
public static void main(String[] args) {
final String usage = """
Usage:
Where:
tableName - The Amazon DynamoDB table in which an item is placed (for example, Music3).
key - The key used in the Amazon DynamoDB table (for example, Artist).
keyval - The key value that represents the item to get (for example, Famous Band).
albumTitle - The Album title (for example, AlbumTitle).
AlbumTitleValue - The name of the album (for example, Songs About Life ).
Awards - The awards column (for example, Awards).
AwardVal - The value of the awards (for example, 10).
SongTitle - The song title (for example, SongTitle).
SongTitleVal - The value of the song title (for example, Happy Day).
**Warning** This program will place an item that you specify into a table!
""";
if (args.length != 9) {
System.out.println(usage);
System.exit(1);
}
String tableName = args[0];
String key = args[1];
String keyVal = args[2];
String albumTitle = args[3];
String albumTitleValue = args[4];
String awards = args[5];
String awardVal = args[6];
String songTitle = args[7];
String songTitleVal = args[8];
Region region = Region.US_EAST_1;
DynamoDbClient ddb = DynamoDbClient.builder()
.region(region)
.build();
putItemInTable(ddb, tableName, key, keyVal, albumTitle, albumTitleValue, awards, awardVal, songTitle,
songTitleVal);
System.out.println("Done!");
ddb.close();
}
public static void putItemInTable(DynamoDbClient ddb,
String tableName,
String key,
String keyVal,
String albumTitle,
String albumTitleValue,
String awards,
String awardVal,
String songTitle,
String songTitleVal) {
HashMap itemValues = new HashMap<>();
itemValues.put(key, AttributeValue.builder().s(keyVal).build());
itemValues.put(songTitle, AttributeValue.builder().s(songTitleVal).build());
itemValues.put(albumTitle, AttributeValue.builder().s(albumTitleValue).build());
itemValues.put(awards, AttributeValue.builder().s(awardVal).build());
PutItemRequest request = PutItemRequest.builder()
.tableName(tableName)
.item(itemValues)
.build();
try {
PutItemResponse response = ddb.putItem(request);
System.out.println(tableName + " was successfully updated. The request id is "
+ response.responseMetadata().requestId());
} catch (ResourceNotFoundException e) {
System.err.format("Error: The Amazon DynamoDB table \"%s\" can't be found.\n", tableName);
System.err.println("Be sure that it exists and that you've typed its name correctly!");
System.exit(1);
} catch (DynamoDbException e) {
System.err.println(e.getMessage());
System.exit(1);
}
}
}
```
+ 有关 API 详细信息，请参阅《AWS SDK for Java 2.x API Reference》**中的 [PutItem](https://docs.aws.amazon.com/goto/SdkForJavaV2/dynamodb-2012-08-10/PutItem)。
------
#### [ JavaScript ]
**SDK for JavaScript (v3)**
查看 GitHub，了解更多信息。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javascriptv3/example_code/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
此示例使用文档客户端来简化在 DynamoDB 中处理项目的过程。有关 API 详细信息，请参阅 [PutCommand](https://docs.aws.amazon.com/AWSJavaScriptSDK/v3/latest/Package/-aws-sdk-lib-dynamodb/Class/PutCommand/)。
```
import { DynamoDBClient } from "@aws-sdk/client-dynamodb";
import { PutCommand, DynamoDBDocumentClient } from "@aws-sdk/lib-dynamodb";
const client = new DynamoDBClient({});
const docClient = DynamoDBDocumentClient.from(client);
export const main = async () => {
const command = new PutCommand({
TableName: "HappyAnimals",
Item: {
CommonName: "Shiba Inu",
},
});
const response = await docClient.send(command);
console.log(response);
return response;
};
```
+ 有关 API 详细信息，请参阅《适用于 JavaScript 的 AWS SDK API Reference》**中的 [PutItem](https://docs.aws.amazon.com/AWSJavaScriptSDK/v3/latest/client/dynamodb/command/PutItemCommand)。
**SDK for JavaScript (v2)**
查看 GitHub，了解更多信息。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javascript/example_code/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
将项目放入表中。
```
// Load the AWS SDK for Node.js
var AWS = require("aws-sdk");
// Set the region
AWS.config.update({ region: "REGION" });
// Create the DynamoDB service object
var ddb = new AWS.DynamoDB({ apiVersion: "2012-08-10" });
var params = {
TableName: "CUSTOMER_LIST",
Item: {
CUSTOMER_ID: { N: "001" },
CUSTOMER_NAME: { S: "Richard Roe" },
},
};
// Call DynamoDB to add the item to the table
ddb.putItem(params, function (err, data) {
if (err) {
console.log("Error", err);
} else {
console.log("Success", data);
}
});
```
使用 DynamoDB 文档客户端将项目放入表中。
```
// Load the AWS SDK for Node.js
var AWS = require("aws-sdk");
// Set the region
AWS.config.update({ region: "REGION" });
// Create DynamoDB document client
var docClient = new AWS.DynamoDB.DocumentClient({ apiVersion: "2012-08-10" });
var params = {
TableName: "TABLE",
Item: {
HASHKEY: VALUE,
ATTRIBUTE_1: "STRING_VALUE",
ATTRIBUTE_2: VALUE_2,
},
};
docClient.put(params, function (err, data) {
if (err) {
console.log("Error", err);
} else {
console.log("Success", data);
}
});
```
+ 有关更多信息，请参阅《适用于 JavaScript 的 AWS SDK 开发人员指南》[https://docs.aws.amazon.com/sdk-for-javascript/v2/developer-guide/dynamodb-example-table-read-write.html#dynamodb-example-table-read-write-writing-an-item](https://docs.aws.amazon.com/sdk-for-javascript/v2/developer-guide/dynamodb-example-table-read-write.html#dynamodb-example-table-read-write-writing-an-item)。
+ 有关 API 详细信息，请参阅《适用于 JavaScript 的 AWS SDK API Reference》**中的 [PutItem](https://docs.aws.amazon.com/goto/AWSJavaScriptSDK/dynamodb-2012-08-10/PutItem)。
------
#### [ Kotlin ]
**SDK for Kotlin**
查看 GitHub，了解更多信息。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/kotlin/services/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
```
suspend fun putItemInTable(
tableNameVal: String,
key: String,
keyVal: String,
albumTitle: String,
albumTitleValue: String,
awards: String,
awardVal: String,
songTitle: String,
songTitleVal: String,
) {
val itemValues = mutableMapOf()
// Add all content to the table.
itemValues[key] = AttributeValue.S(keyVal)
itemValues[songTitle] = AttributeValue.S(songTitleVal)
itemValues[albumTitle] = AttributeValue.S(albumTitleValue)
itemValues[awards] = AttributeValue.S(awardVal)
val request =
PutItemRequest {
tableName = tableNameVal
item = itemValues
}
DynamoDbClient.fromEnvironment { region = "us-east-1" }.use { ddb ->
ddb.putItem(request)
println(" A new item was placed into $tableNameVal.")
}
}
```
+ 有关 API 详细信息，请参阅《AWS SDK for Kotlin API Reference》**中的 [PutItem](https://sdk.amazonaws.com/kotlin/api/latest/index.html)。
------
#### [ PHP ]
**适用于 PHP 的 SDK**
查看 GitHub，了解更多信息。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/php/example_code/dynamodb#code-examples) 中查找完整示例，了解如何进行设置和运行。
```
echo "What's the name of the last movie you watched?\n";
while (empty($movieName)) {
$movieName = testable_readline("Movie name: ");
}
echo "And what year was it released?\n";
$movieYear = "year";
while (!is_numeric($movieYear) || intval($movieYear) != $movieYear) {
$movieYear = testable_readline("Year released: ");
}
$service->putItem([
'Item' => [
'year' => [
'N' => "$movieYear",
],
'title' => [
'S' => $movieName,
],
],
'TableName' => $tableName,
]);
public function putItem(array $array)
{
$this->dynamoDbClient->putItem($array);
}
```
+ 有关 API 详细信息，请参阅《适用于 PHP 的 AWS SDK API Reference》**中的 [PutItem](https://docs.aws.amazon.com/goto/SdkForPHPV3/dynamodb-2012-08-10/PutItem)。
------
#### [ PowerShell ]
**适用于 PowerShell V4 的工具**
**示例 1：创建一个新项目，或将现有项目替换为新项目。**
```
$item = @{
SongTitle = 'Somewhere Down The Road'
Artist = 'No One You Know'
AlbumTitle = 'Somewhat Famous'
Price = 1.94
Genre = 'Country'
CriticRating = 9.0
} | ConvertTo-DDBItem
Set-DDBItem -TableName 'Music' -Item $item
```
+ 有关 API 详细信息，请参阅《AWS Tools for PowerShell Cmdlet Reference (V4)》**中的 [PutItem](https://docs.aws.amazon.com/powershell/v4/reference)。
**适用于 PowerShell V5 的工具**
**示例 1：创建一个新项目，或将现有项目替换为新项目。**
```
$item = @{
SongTitle = 'Somewhere Down The Road'
Artist = 'No One You Know'
AlbumTitle = 'Somewhat Famous'
Price = 1.94
Genre = 'Country'
CriticRating = 9.0
} | ConvertTo-DDBItem
Set-DDBItem -TableName 'Music' -Item $item
```
+ 有关 API 详细信息，请参阅《AWS Tools for PowerShell Cmdlet Reference (V5)》**中的 [PutItem](https://docs.aws.amazon.com/powershell/v5/reference)。
------
#### [ Python ]
**适用于 Python 的 SDK（Boto3）**
查看 GitHub，了解更多信息。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/python/example_code/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
```
class Movies:
"""Encapsulates an Amazon DynamoDB table of movie data.
Example data structure for a movie record in this table:
{
"year": 1999,
"title": "For Love of the Game",
"info": {
"directors": ["Sam Raimi"],
"release_date": "1999-09-15T00:00:00Z",
"rating": 6.3,
"plot": "A washed up pitcher flashes through his career.",
"rank": 4987,
"running_time_secs": 8220,
"actors": [
"Kevin Costner",
"Kelly Preston",
"John C. Reilly"
]
}
}
"""
def __init__(self, dyn_resource):
"""
:param dyn_resource: A Boto3 DynamoDB resource.
"""
self.dyn_resource = dyn_resource
# The table variable is set during the scenario in the call to
# 'exists' if the table exists. Otherwise, it is set by 'create_table'.
self.table = None
def add_movie(self, title, year, plot, rating):
"""
Adds a movie to the table.
:param title: The title of the movie.
:param year: The release year of the movie.
:param plot: The plot summary of the movie.
:param rating: The quality rating of the movie.
"""
try:
self.table.put_item(
Item={
"year": year,
"title": title,
"info": {"plot": plot, "rating": Decimal(str(rating))},
}
)
except ClientError as err:
logger.error(
"Couldn't add movie %s to table %s. Here's why: %s: %s",
title,
self.table.name,
err.response["Error"]["Code"],
err.response["Error"]["Message"],
)
raise
```
+ 有关 API 详细信息，请参阅《AWS SDK for Python (Boto3) API Reference》**中的 [PutItem](https://docs.aws.amazon.com/goto/boto3/dynamodb-2012-08-10/PutItem)。
------
#### [ Ruby ]
**适用于 Ruby 的 SDK**
查看 GitHub，了解更多信息。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/ruby/example_code/dynamodb#code-examples) 中查找完整示例，了解如何进行设置和运行。
```
class DynamoDBBasics
attr_reader :dynamo_resource, :table
def initialize(table_name)
client = Aws::DynamoDB::Client.new(region: 'us-east-1')
@dynamo_resource = Aws::DynamoDB::Resource.new(client: client)
@table = @dynamo_resource.table(table_name)
end
# Adds a movie to the table.
#
# @param movie [Hash] The title, year, plot, and rating of the movie.
def add_item(movie)
@table.put_item(
item: {
'year' => movie[:year],
'title' => movie[:title],
'info' => { 'plot' => movie[:plot], 'rating' => movie[:rating] }
}
)
rescue Aws::DynamoDB::Errors::ServiceError => e
puts("Couldn't add movie #{title} to table #{@table.name}. Here's why:")
puts("\t#{e.code}: #{e.message}")
raise
end
```
+ 有关 API 详细信息，请参阅《适用于 Ruby 的 AWS SDK API Reference》**中的 [PutItem](https://docs.aws.amazon.com/goto/SdkForRubyV3/dynamodb-2012-08-10/PutItem)。
------
#### [ Rust ]
**适用于 Rust 的 SDK**
查看 GitHub，了解更多信息。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/rustv1/examples/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
```
pub async fn add_item(client: &Client, item: Item, table: &String) -> Result {
let user_av = AttributeValue::S(item.username);
let type_av = AttributeValue::S(item.p_type);
let age_av = AttributeValue::S(item.age);
let first_av = AttributeValue::S(item.first);
let last_av = AttributeValue::S(item.last);
let request = client
.put_item()
.table_name(table)
.item("username", user_av)
.item("account_type", type_av)
.item("age", age_av)
.item("first_name", first_av)
.item("last_name", last_av);
println!("Executing request [{request:?}] to add item...");
let resp = request.send().await?;
let attributes = resp.attributes().unwrap();
let username = attributes.get("username").cloned();
let first_name = attributes.get("first_name").cloned();
let last_name = attributes.get("last_name").cloned();
let age = attributes.get("age").cloned();
let p_type = attributes.get("p_type").cloned();
println!(
"Added user {:?}, {:?} {:?}, age {:?} as {:?} user",
username, first_name, last_name, age, p_type
);
Ok(ItemOut {
p_type,
age,
username,
first_name,
last_name,
})
}
```
+ 有关 API 详细信息，请参阅《AWS SDK for Rust API Reference》**中的 [PutItem](https://docs.rs/aws-sdk-dynamodb/latest/aws_sdk_dynamodb/client/struct.Client.html#method.put_item)。
------
#### [ SAP ABAP ]
**适用于 SAP ABAP 的 SDK**
查看 GitHub，了解更多信息。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/sap-abap/services/dyn#code-examples)中查找完整示例，了解如何进行设置和运行。
```
TRY.
DATA(lo_resp) = lo_dyn->putitem(
iv_tablename = iv_table_name
it_item = it_item ).
MESSAGE '1 row inserted into DynamoDB Table' && iv_table_name TYPE 'I'.
CATCH /aws1/cx_dyncondalcheckfaile00.
MESSAGE 'A condition specified in the operation could not be evaluated.' TYPE 'E'.
CATCH /aws1/cx_dynresourcenotfoundex.
MESSAGE 'The table or index does not exist' TYPE 'E'.
CATCH /aws1/cx_dyntransactconflictex.
MESSAGE 'Another transaction is using the item' TYPE 'E'.
ENDTRY.
```
+ 有关 API 详细信息，请参阅《AWS SDK for SAP ABAP API Reference》**中的 [PutItem](https://docs.aws.amazon.com/sdk-for-sap-abap/v1/api/latest/index.html)。
------
#### [ Swift ]
**适用于 Swift 的 SDK**
查看 GitHub，了解更多信息。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/swift/example_code/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
```
import AWSDynamoDB
/// Add a movie specified as a `Movie` structure to the Amazon DynamoDB
/// table.
///
/// - Parameter movie: The `Movie` to add to the table.
///
func add(movie: Movie) async throws {
do {
guard let client = self.ddbClient else {
throw MoviesError.UninitializedClient
}
// Get a DynamoDB item containing the movie data.
let item = try await movie.getAsItem()
// Send the `PutItem` request to Amazon DynamoDB.
let input = PutItemInput(
item: item,
tableName: self.tableName
)
_ = try await client.putItem(input: input)
} catch {
print("ERROR: add movie:", dump(error))
throw error
}
}
///
/// Return an array mapping attribute names to Amazon DynamoDB attribute
/// values, representing the contents of the `Movie` record as a DynamoDB
/// item.
///
/// - Returns: The movie item as an array of type
/// `[Swift.String:DynamoDBClientTypes.AttributeValue]`.
///
func getAsItem() async throws -> [Swift.String:DynamoDBClientTypes.AttributeValue] {
// Build the item record, starting with the year and title, which are
// always present.
var item: [Swift.String:DynamoDBClientTypes.AttributeValue] = [
"year": .n(String(self.year)),
"title": .s(self.title)
]
// Add the `info` field with the rating and/or plot if they're
// available.
var details: [Swift.String:DynamoDBClientTypes.AttributeValue] = [:]
if (self.info.rating != nil || self.info.plot != nil) {
if self.info.rating != nil {
details["rating"] = .n(String(self.info.rating!))
}
if self.info.plot != nil {
details["plot"] = .s(self.info.plot!)
}
}
item["info"] = .m(details)
return item
}
```
+ 有关 API 详细信息，请参阅《AWS SDK for Swift API 参考》**中的 [PutItem](https://sdk.amazonaws.com/swift/api/awsdynamodb/latest/documentation/awsdynamodb/dynamodbclient/putitem(input:))。
------
有关 AWS SDK 开发人员指南和代码示例的完整列表，请参阅 [结合使用 DynamoDB 与 AWS SDK](sdk-general-information-section.md) 本主题还包括有关入门的信息以及有关先前的 SDK 版本的详细信息。
# 将 `Query` 与 AWS SDK 或 CLI 配合使用
以下代码示例演示如何使用 `Query`。
操作示例是大型程序的代码摘录，必须在上下文中运行。您可以在以下代码示例中查看此操作的上下文：
+ [了解基本功能](example_dynamodb_Scenario_GettingStartedMovies_section.md)
+ [借助 DAX 加快读取速度](example_dynamodb_Usage_DaxDemo_section.md)
+ [高级全局二级索引方案](example_dynamodb_Scenario_GSIAdvanced_section.md)
+ [将多个值与单个属性进行比较](example_dynamodb_Scenario_CompareMultipleValues_section.md)
+ [管理全局二级索引](example_dynamodb_Scenario_GSILifecycle_section.md)
+ [执行高级查询操作](example_dynamodb_Scenario_AdvancedQueryTechniques_section.md)
+ [使用 begins\$1with 条件查询表](example_dynamodb_Scenarios_QueryWithBeginsWithCondition_section.md)
+ [使用日期范围查询表](example_dynamodb_Scenarios_QueryWithDateRange_section.md)
+ [使用全局二级索引查询表](example_dynamodb_Scenarios_QueryWithGlobalSecondaryIndex_section.md)
+ [使用复杂的筛选表达式查询表](example_dynamodb_Scenarios_QueryWithComplexFilter_section.md)
+ [使用动态筛选表达式查询表](example_dynamodb_Scenarios_QueryWithDynamicFilter_section.md)
+ [使用筛选表达式和限制查询表](example_dynamodb_Scenarios_QueryWithFilterAndLimit_section.md)
+ [使用嵌套属性查询表](example_dynamodb_Scenarios_QueryWithNestedAttributes_section.md)
+ [通过分区查询表](example_dynamodb_Scenarios_QueryWithPagination_section.md)
+ [通过强一致性读取查询表](example_dynamodb_Scenarios_QueryWithStronglyConsistentReads_section.md)
+ [查询 TTL 项目](example_dynamodb_QueryFilteredTTL_section.md)
+ [使用日期和时间模式查询表](example_dynamodb_Scenario_DateTimeQueries_section.md)
+ [使用表达式属性名称](example_dynamodb_Scenario_ExpressionAttributeNames_section.md)
+ [处理本地二级索引](example_dynamodb_Scenario_LSIExamples_section.md)
------
#### [ .NET ]
**适用于 .NET 的 SDK (v4)**
查看 GitHub，了解更多信息。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/dotnetv4/DynamoDB#code-examples) 中查找完整示例，了解如何进行设置和运行。
```
///
/// Queries the table for movies released in a particular year and
/// then displays the information for the movies returned.
///
/// The name of the table to query.
/// The release year for which we want to
/// view movies.
/// The number of movies that match the query.
public async Task QueryMoviesAsync(string tableName, int year)
{
try
{
var movieTable = new TableBuilder(_amazonDynamoDB, tableName)
.AddHashKey("year", DynamoDBEntryType.Numeric)
.AddRangeKey("title", DynamoDBEntryType.String)
.Build();
var filter = new QueryFilter("year", QueryOperator.Equal, year);
Console.WriteLine("\nFind movies released in: {year}:");
var config = new QueryOperationConfig()
{
Limit = 10, // 10 items per page.
Select = SelectValues.SpecificAttributes,
AttributesToGet = new List
{
"title",
"year",
},
ConsistentRead = true,
Filter = filter,
};
// Value used to track how many movies match the
// supplied criteria.
var moviesFound = 0;
var search = movieTable.Query(config);
do
{
var movieList = await search.GetNextSetAsync();
moviesFound += movieList.Count;
foreach (var movie in movieList)
{
DisplayDocument(movie);
}
}
while (!search.IsDone);
return moviesFound;
}
catch (ResourceNotFoundException ex)
{
Console.WriteLine($"Table {tableName} was not found. {ex.Message}");
return 0;
}
catch (AmazonDynamoDBException ex)
{
Console.WriteLine($"An Amazon DynamoDB error occurred while querying movies. {ex.Message}");
throw;
}
catch (Exception ex)
{
Console.WriteLine($"An error occurred while querying movies. {ex.Message}");
throw;
}
}
```
+ 有关 API 详细信息，请参阅《适用于 .NET 的 AWS SDK API Reference》**中的 [Query](https://docs.aws.amazon.com/goto/DotNetSDKV4/dynamodb-2012-08-10/Query)。
------
#### [ Bash ]
**AWS CLI 及 Bash 脚本**
查看 GitHub，了解更多信息。查找完整示例，了解如何在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/aws-cli/bash-linux/dynamodb#code-examples)中进行设置和运行。
```
#############################################################################
# function dynamodb_query
#
# This function queries a DynamoDB table.
#
# Parameters:
# -n table_name -- The name of the table.
# -k key_condition_expression -- The key condition expression.
# -a attribute_names -- Path to JSON file containing the attribute names.
# -v attribute_values -- Path to JSON file containing the attribute values.
# [-p projection_expression] -- Optional projection expression.
#
# Returns:
# The items as json output.
# And:
# 0 - If successful.
# 1 - If it fails.
###########################################################################
function dynamodb_query() {
local table_name key_condition_expression attribute_names attribute_values projection_expression response
local option OPTARG # Required to use getopts command in a function.
# ######################################
# Function usage explanation
#######################################
function usage() {
echo "function dynamodb_query"
echo "Query a DynamoDB table."
echo " -n table_name -- The name of the table."
echo " -k key_condition_expression -- The key condition expression."
echo " -a attribute_names -- Path to JSON file containing the attribute names."
echo " -v attribute_values -- Path to JSON file containing the attribute values."
echo " [-p projection_expression] -- Optional projection expression."
echo ""
}
while getopts "n:k:a:v:p:h" option; do
case "${option}" in
n) table_name="${OPTARG}" ;;
k) key_condition_expression="${OPTARG}" ;;
a) attribute_names="${OPTARG}" ;;
v) attribute_values="${OPTARG}" ;;
p) projection_expression="${OPTARG}" ;;
h)
usage
return 0
;;
\?)
echo "Invalid parameter"
usage
return 1
;;
esac
done
export OPTIND=1
if [[ -z "$table_name" ]]; then
errecho "ERROR: You must provide a table name with the -n parameter."
usage
return 1
fi
if [[ -z "$key_condition_expression" ]]; then
errecho "ERROR: You must provide a key condition expression with the -k parameter."
usage
return 1
fi
if [[ -z "$attribute_names" ]]; then
errecho "ERROR: You must provide a attribute names with the -a parameter."
usage
return 1
fi
if [[ -z "$attribute_values" ]]; then
errecho "ERROR: You must provide a attribute values with the -v parameter."
usage
return 1
fi
if [[ -z "$projection_expression" ]]; then
response=$(aws dynamodb query \
--table-name "$table_name" \
--key-condition-expression "$key_condition_expression" \
--expression-attribute-names file://"$attribute_names" \
--expression-attribute-values file://"$attribute_values")
else
response=$(aws dynamodb query \
--table-name "$table_name" \
--key-condition-expression "$key_condition_expression" \
--expression-attribute-names file://"$attribute_names" \
--expression-attribute-values file://"$attribute_values" \
--projection-expression "$projection_expression")
fi
local error_code=${?}
if [[ $error_code -ne 0 ]]; then
aws_cli_error_log $error_code
errecho "ERROR: AWS reports query operation failed.$response"
return 1
fi
echo "$response"
return 0
}
```
本示例中使用的实用程序函数。
```
###############################################################################
# function errecho
#
# This function outputs everything sent to it to STDERR (standard error output).
###############################################################################
function errecho() {
printf "%s\n" "$*" 1>&2
}
##############################################################################
# function aws_cli_error_log()
#
# This function is used to log the error messages from the AWS CLI.
#
# See https://docs.aws.amazon.com/cli/latest/topic/return-codes.html#cli-aws-help-return-codes.
#
# The function expects the following argument:
# $1 - The error code returned by the AWS CLI.
#
# Returns:
# 0: - Success.
#
##############################################################################
function aws_cli_error_log() {
local err_code=$1
errecho "Error code : $err_code"
if [ "$err_code" == 1 ]; then
errecho " One or more S3 transfers failed."
elif [ "$err_code" == 2 ]; then
errecho " Command line failed to parse."
elif [ "$err_code" == 130 ]; then
errecho " Process received SIGINT."
elif [ "$err_code" == 252 ]; then
errecho " Command syntax invalid."
elif [ "$err_code" == 253 ]; then
errecho " The system environment or configuration was invalid."
elif [ "$err_code" == 254 ]; then
errecho " The service returned an error."
elif [ "$err_code" == 255 ]; then
errecho " 255 is a catch-all error."
fi
return 0
}
```
+ 有关 API 详细信息，请参阅《AWS CLI 命令参考》**中的 [Query](https://docs.aws.amazon.com/goto/aws-cli/dynamodb-2012-08-10/Query)。
------
#### [ C\$1\$1 ]
**SDK for C\$1\$1**
查看 GitHub，了解更多信息。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/cpp/example_code/dynamodb#code-examples) 中查找完整示例，了解如何进行设置和运行。
```
//! Perform a query on an Amazon DynamoDB Table and retrieve items.
/*!
\sa queryItem()
\param tableName: The table name.
\param partitionKey: The partition key.
\param partitionValue: The value for the partition key.
\param projectionExpression: The projections expression, which is ignored if empty.
\param clientConfiguration: AWS client configuration.
\return bool: Function succeeded.
*/
/*
* The partition key attribute is searched with the specified value. By default, all fields and values
* contained in the item are returned. If an optional projection expression is
* specified on the command line, only the specified fields and values are
* returned.
*/
bool AwsDoc::DynamoDB::queryItems(const Aws::String &tableName,
const Aws::String &partitionKey,
const Aws::String &partitionValue,
const Aws::String &projectionExpression,
const Aws::Client::ClientConfiguration &clientConfiguration) {
Aws::DynamoDB::DynamoDBClient dynamoClient(clientConfiguration);
Aws::DynamoDB::Model::QueryRequest request;
request.SetTableName(tableName);
if (!projectionExpression.empty()) {
request.SetProjectionExpression(projectionExpression);
}
// Set query key condition expression.
request.SetKeyConditionExpression(partitionKey + "= :valueToMatch");
// Set Expression AttributeValues.
Aws::Map attributeValues;
attributeValues.emplace(":valueToMatch", partitionValue);
request.SetExpressionAttributeValues(attributeValues);
bool result = true;
// "exclusiveStartKey" is used for pagination.
Aws::Map exclusiveStartKey;
do {
if (!exclusiveStartKey.empty()) {
request.SetExclusiveStartKey(exclusiveStartKey);
exclusiveStartKey.clear();
}
// Perform Query operation.
const Aws::DynamoDB::Model::QueryOutcome &outcome = dynamoClient.Query(request);
if (outcome.IsSuccess()) {
// Reference the retrieved items.
const Aws::Vector> &items = outcome.GetResult().GetItems();
if (!items.empty()) {
std::cout << "Number of items retrieved from Query: " << items.size()
<< std::endl;
// Iterate each item and print.
for (const auto &item: items) {
std::cout
<< "******************************************************"
<< std::endl;
// Output each retrieved field and its value.
for (const auto &i: item)
std::cout << i.first << ": " << i.second.GetS() << std::endl;
}
}
else {
std::cout << "No item found in table: " << tableName << std::endl;
}
exclusiveStartKey = outcome.GetResult().GetLastEvaluatedKey();
}
else {
std::cerr << "Failed to Query items: " << outcome.GetError().GetMessage();
result = false;
break;
}
} while (!exclusiveStartKey.empty());
return result;
}
```
+ 有关 API 详细信息，请参阅 *适用于 C\$1\$1 的 AWS SDK API 参考*中的 [Query](https://docs.aws.amazon.com/goto/SdkForCpp/dynamodb-2012-08-10/Query)。
------
#### [ CLI ]
**AWS CLI**
**示例 1：查询表**
以下 `query` 示例查询 `MusicCollection` 表中的项。该表具有 hash-and-range 主键（`Artist` 和 `SongTitle`），但此查询仅指定哈希键值。它返回名为“No One You Know”的艺术家的歌名。
```
aws dynamodb query \
--table-name MusicCollection \
--projection-expression "SongTitle" \
--key-condition-expression "Artist = :v1" \
--expression-attribute-values file://expression-attributes.json \
--return-consumed-capacity TOTAL
```
的内容`expression-attributes.json`：
```
{
":v1": {"S": "No One You Know"}
}
```
输出：
```
{
"Items": [
{
"SongTitle": {
"S": "Call Me Today"
},
"SongTitle": {
"S": "Scared of My Shadow"
}
}
],
"Count": 2,
"ScannedCount": 2,
"ConsumedCapacity": {
"TableName": "MusicCollection",
"CapacityUnits": 0.5
}
}
```
有关更多信息，请参阅《Amazon DynamoDB 开发人员指南》**中的[使用 DynamoDB 中的查询](https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/Query.html)。
**示例 2：使用强一致性读取查询表并按降序遍历索引**
以下示例执行与第一个示例相同的查询，但返回结果的顺序相反，并且使用强一致性读取。
```
aws dynamodb query \
--table-name MusicCollection \
--projection-expression "SongTitle" \
--key-condition-expression "Artist = :v1" \
--expression-attribute-values file://expression-attributes.json \
--consistent-read \
--no-scan-index-forward \
--return-consumed-capacity TOTAL
```
的内容`expression-attributes.json`：
```
{
":v1": {"S": "No One You Know"}
}
```
输出：
```
{
"Items": [
{
"SongTitle": {
"S": "Scared of My Shadow"
}
},
{
"SongTitle": {
"S": "Call Me Today"
}
}
],
"Count": 2,
"ScannedCount": 2,
"ConsumedCapacity": {
"TableName": "MusicCollection",
"CapacityUnits": 1.0
}
}
```
有关更多信息，请参阅《Amazon DynamoDB 开发人员指南》**中的[使用 DynamoDB 中的查询](https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/Query.html)。
**示例 3：筛选出特定结果**
以下示例查询 `MusicCollection`，但不包括 `AlbumTitle` 属性中含特定值的结果。请注意，这不会影响 `ScannedCount` 或 `ConsumedCapacity`，因为筛选器在读取项之后应用。
```
aws dynamodb query \
--table-name MusicCollection \
--key-condition-expression "#n1 = :v1" \
--filter-expression "NOT (#n2 IN (:v2, :v3))" \
--expression-attribute-names file://names.json \
--expression-attribute-values file://values.json \
--return-consumed-capacity TOTAL
```
的内容`values.json`：
```
{
":v1": {"S": "No One You Know"},
":v2": {"S": "Blue Sky Blues"},
":v3": {"S": "Greatest Hits"}
}
```
的内容`names.json`：
```
{
"#n1": "Artist",
"#n2": "AlbumTitle"
}
```
输出：
```
{
"Items": [
{
"AlbumTitle": {
"S": "Somewhat Famous"
},
"Artist": {
"S": "No One You Know"
},
"SongTitle": {
"S": "Call Me Today"
}
}
],
"Count": 1,
"ScannedCount": 2,
"ConsumedCapacity": {
"TableName": "MusicCollection",
"CapacityUnits": 0.5
}
}
```
有关更多信息，请参阅《Amazon DynamoDB 开发人员指南》**中的[使用 DynamoDB 中的查询](https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/Query.html)。
**示例 4：仅检索项计数**
以下示例检索与查询匹配的项计数，但不检索任何项本身。
```
aws dynamodb query \
--table-name MusicCollection \
--select COUNT \
--key-condition-expression "Artist = :v1" \
--expression-attribute-values file://expression-attributes.json
```
的内容`expression-attributes.json`：
```
{
":v1": {"S": "No One You Know"}
}
```
输出：
```
{
"Count": 2,
"ScannedCount": 2,
"ConsumedCapacity": null
}
```
有关更多信息，请参阅《Amazon DynamoDB 开发人员指南》**中的[使用 DynamoDB 中的查询](https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/Query.html)。
**示例 5：查询索引**
以下示例查询本地二级索引 `AlbumTitleIndex`。该查询返回基表中已投影到本地二级索引的所有属性。请注意，查询本地二级索引或全局二级索引时，您还必须使用 `table-name` 参数提供基表的名称。
```
aws dynamodb query \
--table-name MusicCollection \
--index-name AlbumTitleIndex \
--key-condition-expression "Artist = :v1" \
--expression-attribute-values file://expression-attributes.json \
--select ALL_PROJECTED_ATTRIBUTES \
--return-consumed-capacity INDEXES
```
的内容`expression-attributes.json`：
```
{
":v1": {"S": "No One You Know"}
}
```
输出：
```
{
"Items": [
{
"AlbumTitle": {
"S": "Blue Sky Blues"
},
"Artist": {
"S": "No One You Know"
},
"SongTitle": {
"S": "Scared of My Shadow"
}
},
{
"AlbumTitle": {
"S": "Somewhat Famous"
},
"Artist": {
"S": "No One You Know"
},
"SongTitle": {
"S": "Call Me Today"
}
}
],
"Count": 2,
"ScannedCount": 2,
"ConsumedCapacity": {
"TableName": "MusicCollection",
"CapacityUnits": 0.5,
"Table": {
"CapacityUnits": 0.0
},
"LocalSecondaryIndexes": {
"AlbumTitleIndex": {
"CapacityUnits": 0.5
}
}
}
}
```
有关更多信息，请参阅《Amazon DynamoDB 开发人员指南》**中的[使用 DynamoDB 中的查询](https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/Query.html)。
+ 有关 API 详细信息，请参阅《AWS CLI 命令参考》**中的 [Query](https://awscli.amazonaws.com/v2/documentation/api/latest/reference/dynamodb/query.html)。
------
#### [ Go ]
**适用于 Go 的 SDK V2**
查看 GitHub，了解更多信息。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/gov2/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
```
import (
"context"
"errors"
"log"
"time"
"github.com/aws/aws-sdk-go-v2/aws"
"github.com/aws/aws-sdk-go-v2/feature/dynamodb/attributevalue"
"github.com/aws/aws-sdk-go-v2/feature/dynamodb/expression"
"github.com/aws/aws-sdk-go-v2/service/dynamodb"
"github.com/aws/aws-sdk-go-v2/service/dynamodb/types"
)
// TableBasics encapsulates the Amazon DynamoDB service actions used in the examples.
// It contains a DynamoDB service client that is used to act on the specified table.
type TableBasics struct {
DynamoDbClient *dynamodb.Client
TableName string
}
// Query gets all movies in the DynamoDB table that were released in the specified year.
// The function uses the `expression` package to build the key condition expression
// that is used in the query.
func (basics TableBasics) Query(ctx context.Context, releaseYear int) ([]Movie, error) {
var err error
var response *dynamodb.QueryOutput
var movies []Movie
keyEx := expression.Key("year").Equal(expression.Value(releaseYear))
expr, err := expression.NewBuilder().WithKeyCondition(keyEx).Build()
if err != nil {
log.Printf("Couldn't build expression for query. Here's why: %v\n", err)
} else {
queryPaginator := dynamodb.NewQueryPaginator(basics.DynamoDbClient, &dynamodb.QueryInput{
TableName: aws.String(basics.TableName),
ExpressionAttributeNames: expr.Names(),
ExpressionAttributeValues: expr.Values(),
KeyConditionExpression: expr.KeyCondition(),
})
for queryPaginator.HasMorePages() {
response, err = queryPaginator.NextPage(ctx)
if err != nil {
log.Printf("Couldn't query for movies released in %v. Here's why: %v\n", releaseYear, err)
break
} else {
var moviePage []Movie
err = attributevalue.UnmarshalListOfMaps(response.Items, &moviePage)
if err != nil {
log.Printf("Couldn't unmarshal query response. Here's why: %v\n", err)
break
} else {
movies = append(movies, moviePage...)
}
}
}
}
return movies, err
}
```
定义本示例中使用的 Movie 结构。
```
import (
"archive/zip"
"bytes"
"encoding/json"
"fmt"
"io"
"log"
"net/http"
"github.com/aws/aws-sdk-go-v2/feature/dynamodb/attributevalue"
"github.com/aws/aws-sdk-go-v2/service/dynamodb/types"
)
// Movie encapsulates data about a movie. Title and Year are the composite primary key
// of the movie in Amazon DynamoDB. Title is the sort key, Year is the partition key,
// and Info is additional data.
type Movie struct {
Title string `dynamodbav:"title"`
Year int `dynamodbav:"year"`
Info map[string]interface{} `dynamodbav:"info"`
}
// GetKey returns the composite primary key of the movie in a format that can be
// sent to DynamoDB.
func (movie Movie) GetKey() map[string]types.AttributeValue {
title, err := attributevalue.Marshal(movie.Title)
if err != nil {
panic(err)
}
year, err := attributevalue.Marshal(movie.Year)
if err != nil {
panic(err)
}
return map[string]types.AttributeValue{"title": title, "year": year}
}
// String returns the title, year, rating, and plot of a movie, formatted for the example.
func (movie Movie) String() string {
return fmt.Sprintf("%v\n\tReleased: %v\n\tRating: %v\n\tPlot: %v\n",
movie.Title, movie.Year, movie.Info["rating"], movie.Info["plot"])
}
```
+ 有关 API 详细信息，请参阅《适用于 Go 的 AWS SDK API Reference》**中的 [Query](https://pkg.go.dev/github.com/aws/aws-sdk-go-v2/service/dynamodb#Client.Query)。
------
#### [ Java ]
**适用于 Java 的 SDK 2.x**
查看 GitHub，了解更多信息。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javav2/example_code/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
使用 [DynamoDbClient](https://docs.aws.amazon.com/sdk-for-java/latest/reference/software/amazon/awssdk/services/dynamodb/DynamoDbClient.html) 查询表。
```
import software.amazon.awssdk.regions.Region;
import software.amazon.awssdk.services.dynamodb.DynamoDbClient;
import software.amazon.awssdk.services.dynamodb.model.AttributeValue;
import software.amazon.awssdk.services.dynamodb.model.DynamoDbException;
import software.amazon.awssdk.services.dynamodb.model.QueryRequest;
import software.amazon.awssdk.services.dynamodb.model.QueryResponse;
import java.util.HashMap;
/**
* Before running this Java V2 code example, set up your development
* environment, including your credentials.
*
* For more information, see the following documentation topic:
*
* https://docs.aws.amazon.com/sdk-for-java/latest/developer-guide/get-started.html
*
* To query items from an Amazon DynamoDB table using the AWS SDK for Java V2,
* its better practice to use the
* Enhanced Client. See the EnhancedQueryRecords example.
*/
public class Query {
public static void main(String[] args) {
final String usage = """
Usage: