Les traductions sont fournies par des outils de traduction automatique. En cas de conflit entre le contenu d'une traduction et celui de la version originale en anglais, la version anglaise prévaudra. # Interrogation d'une table DynamoDB à l'aide d'un index secondaire global avec un SDK AWS Les exemples de code suivants montrent comment interroger une table à l’aide d’un index secondaire global. + Interrogation d’une table DynamoDB à l’aide de sa clé primaire. + Interrogez un index secondaires globaux (GSI) pour les autres modèles d’accès. + Comparez les requêtes de table et les requêtes GSI. ------ #### [ Java ] **SDK pour Java 2.x** Interrogez une table DynamoDB à l'aide de sa clé primaire et d'un index secondaire global (GSI) avec. AWS SDK for Java 2.x ``` 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 software.amazon.awssdk.services.dynamodb.model.ResourceNotFoundException; import java.util.HashMap; import java.util.Map; public QueryResponse queryTable( final String tableName, final String partitionKeyName, final String partitionKeyValue) { CodeSampleUtils.validateTableParameters(tableName, partitionKeyName, partitionKeyValue); // Create expression attribute names for the column names final Map expressionAttributeNames = new HashMap<>(); expressionAttributeNames.put(EXPRESSION_ATTRIBUTE_NAME_PK, partitionKeyName); // Create expression attribute values for the column values final Map expressionAttributeValues = new HashMap<>(); expressionAttributeValues.put( EXPRESSION_ATTRIBUTE_VALUE_PK, AttributeValue.builder().s(partitionKeyValue).build()); // Create the query request final QueryRequest queryRequest = QueryRequest.builder() .tableName(tableName) .keyConditionExpression(KEY_CONDITION_EXPRESSION) .expressionAttributeNames(expressionAttributeNames) .expressionAttributeValues(expressionAttributeValues) .build(); try { final QueryResponse response = dynamoDbClient.query(queryRequest); System.out.println("Query on base table successful. Found " + response.count() + " items"); return response; } catch (ResourceNotFoundException e) { System.err.format("Error: The Amazon DynamoDB table \"%s\" can't be found.\n", tableName); throw new DynamoDbQueryException("Table not found: " + tableName, e); } catch (DynamoDbException e) { System.err.println("Error querying base table: " + e.getMessage()); throw new DynamoDbQueryException("Failed to execute query on base table", e); } } /** * Queries a DynamoDB Global Secondary Index (GSI) by partition key. * * @param tableName The name of the DynamoDB table * @param indexName The name of the GSI * @param partitionKeyName The name of the GSI partition key attribute * @param partitionKeyValue The value of the GSI partition key to query * @return The query response from DynamoDB * @throws ResourceNotFoundException if the table or index doesn't exist * @throws DynamoDbException if the query fails */ public QueryResponse queryGlobalSecondaryIndex( final String tableName, final String indexName, final String partitionKeyName, final String partitionKeyValue) { CodeSampleUtils.validateTableParameters(tableName, partitionKeyName, partitionKeyValue); CodeSampleUtils.validateStringParameter("Index name", indexName); // Create expression attribute names for the column names final Map expressionAttributeNames = new HashMap<>(); expressionAttributeNames.put(EXPRESSION_ATTRIBUTE_NAME_IK, partitionKeyName); // Create expression attribute values for the column values final Map expressionAttributeValues = new HashMap<>(); expressionAttributeValues.put( EXPRESSION_ATTRIBUTE_VALUE_IK, AttributeValue.builder().s(partitionKeyValue).build()); // Create the query request final QueryRequest queryRequest = QueryRequest.builder() .tableName(tableName) .indexName(indexName) .keyConditionExpression(GSI_KEY_CONDITION_EXPRESSION) .expressionAttributeNames(expressionAttributeNames) .expressionAttributeValues(expressionAttributeValues) .build(); try { final QueryResponse response = dynamoDbClient.query(queryRequest); System.out.println("Query on GSI successful. Found " + response.count() + " items"); return response; } catch (ResourceNotFoundException e) { System.err.format( "Error: The Amazon DynamoDB table \"%s\" or index \"%s\" can't be found.\n", tableName, indexName); throw new DynamoDbQueryException("Table or index not found: " + tableName + "/" + indexName, e); } catch (DynamoDbException e) { System.err.println("Error querying GSI: " + e.getMessage()); throw new DynamoDbQueryException("Failed to execute query on GSI", e); } } ``` Comparez l'interrogation directe d'une table à l'interrogation d'un GSI avec. AWS SDK for Java 2.x ``` public static void main(String[] args) { final String usage = """ Usage: [region] Where: tableName - The Amazon DynamoDB table to query. basePartitionKeyName - The name of the base table partition key attribute. basePartitionKeyValue - The value of the base table partition key to query. gsiName - The name of the Global Secondary Index. gsiPartitionKeyName - The name of the GSI partition key attribute. gsiPartitionKeyValue - The value of the GSI partition key to query. region (optional) - The AWS region where the table exists. (Default: us-east-1) """; if (args.length < 6) { System.out.println(usage); System.exit(1); } final String tableName = args[0]; final String basePartitionKeyName = args[1]; final String basePartitionKeyValue = args[2]; final String gsiName = args[3]; final String gsiPartitionKeyName = args[4]; final String gsiPartitionKeyValue = args[5]; final Region region = args.length > 6 ? Region.of(args[6]) : Region.US_EAST_1; try (DynamoDbClient ddb = DynamoDbClient.builder().region(region).build()) { final QueryTableAndGSI queryHelper = new QueryTableAndGSI(ddb); // Query the base table System.out.println("Querying base table where " + basePartitionKeyName + " = " + basePartitionKeyValue); final QueryResponse tableResponse = queryHelper.queryTable(tableName, basePartitionKeyName, basePartitionKeyValue); System.out.println("Found " + tableResponse.count() + " items in base table:"); tableResponse.items().forEach(item -> System.out.println(item)); // Query the GSI System.out.println( "\nQuerying GSI '" + gsiName + "' where " + gsiPartitionKeyName + " = " + gsiPartitionKeyValue); final QueryResponse gsiResponse = queryHelper.queryGlobalSecondaryIndex(tableName, gsiName, gsiPartitionKeyName, gsiPartitionKeyValue); System.out.println("Found " + gsiResponse.count() + " items in GSI:"); gsiResponse.items().forEach(item -> System.out.println(item)); // Explain the differences between querying a table and a GSI System.out.println("\nKey differences between querying a table and a GSI:"); System.out.println("1. When querying a GSI, you must specify the indexName parameter"); System.out.println("2. GSIs may not contain all attributes from the base table (projection)"); System.out.println("3. GSIs consume read capacity units from the GSI's capacity, not the base table's"); System.out.println("4. GSIs may have eventually consistent data (cannot use ConsistentRead=true)"); } catch (IllegalArgumentException e) { System.err.println("Invalid input: " + e.getMessage()); System.exit(1); } catch (ResourceNotFoundException e) { System.err.println("Table or index not found: " + e.getMessage()); System.exit(1); } catch (DynamoDbException e) { System.err.println("DynamoDB error: " + e.getMessage()); System.exit(1); } catch (Exception e) { System.err.println("Unexpected error: " + e.getMessage()); System.exit(1); } } ``` + Pour plus d’informations sur l’API, consultez [Requête](https://docs.aws.amazon.com/goto/SdkForJavaV2/dynamodb-2012-08-10/Query) dans la *référence d’API AWS SDK for Java 2.x *. ------ #### [ JavaScript ] **SDK pour JavaScript (v3)** Interrogez une table DynamoDB à l'aide de la clé primaire avec. AWS SDK pour JavaScript ``` const { DynamoDBClient, QueryCommand } = require("@aws-sdk/client-dynamodb"); /** * Queries a DynamoDB table using the primary key * * @param {Object} config - AWS SDK configuration object * @param {string} tableName - The name of the DynamoDB table * @param {string} userId - The user ID to query by (partition key) * @returns {Promise} - The query response */ async function queryTable( config, tableName, userId ) { try { // Create DynamoDB client const client = new DynamoDBClient(config); // Construct the query input for the base table const input = { TableName: tableName, KeyConditionExpression: "user_id = :userId", ExpressionAttributeValues: { ":userId": { S: userId } } }; // Execute the query const command = new QueryCommand(input); return await client.send(command); } catch (error) { console.error(`Error querying table: ${error}`); throw error; } } ``` Interrogez un index secondaire global (GSI) DynamoDB avec. AWS SDK pour JavaScript ``` /** * Queries a DynamoDB Global Secondary Index (GSI) * * @param {Object} config - AWS SDK configuration object * @param {string} tableName - The name of the DynamoDB table * @param {string} indexName - The name of the GSI to query * @param {string} gameId - The game ID to query by (GSI partition key) * @returns {Promise} - The query response */ async function queryGSI( config, tableName, indexName, gameId ) { try { // Create DynamoDB client const client = new DynamoDBClient(config); // Construct the query input for the GSI const input = { TableName: tableName, IndexName: indexName, KeyConditionExpression: "game_id = :gameId", ExpressionAttributeValues: { ":gameId": { S: gameId } } }; // Execute the query const command = new QueryCommand(input); return await client.send(command); } catch (error) { console.error(`Error querying GSI: ${error}`); throw error; } } ``` + Pour plus d’informations sur l’API, consultez [Requête](https://docs.aws.amazon.com/AWSJavaScriptSDK/v3/latest/client/dynamodb/command/QueryCommand) dans la *référence d’API AWS SDK pour JavaScript *. ------ #### [ Python ] **Kit SDK for Python (Boto3)** Interrogez une table DynamoDB à l'aide de sa clé primaire et d'un index secondaire global (GSI) avec. AWS SDK pour Python (Boto3) ``` import boto3 from boto3.dynamodb.conditions import Key def query_table(table_name, partition_key_name, partition_key_value): """ Query a DynamoDB table using its primary key. Args: table_name (str): The name of the DynamoDB table. partition_key_name (str): The name of the partition key attribute. partition_key_value (str): The value of the partition key to query. Returns: dict: The response from DynamoDB containing the query results. """ # Initialize the DynamoDB resource dynamodb = boto3.resource("dynamodb") table = dynamodb.Table(table_name) # Perform the query on the table's primary key response = table.query(KeyConditionExpression=Key(partition_key_name).eq(partition_key_value)) return response def query_gsi(table_name, index_name, partition_key_name, partition_key_value): """ Query a Global Secondary Index (GSI) on a DynamoDB table. Args: table_name (str): The name of the DynamoDB table. index_name (str): The name of the Global Secondary Index. partition_key_name (str): The name of the GSI's partition key attribute. partition_key_value (str): The value of the GSI's partition key to query. Returns: dict: The response from DynamoDB containing the query results. """ # Initialize the DynamoDB resource dynamodb = boto3.resource("dynamodb") table = dynamodb.Table(table_name) # Perform the query on the GSI response = table.query( IndexName=index_name, KeyConditionExpression=Key(partition_key_name).eq(partition_key_value) ) return response ``` + Pour de plus amples informations sur l’API, consultez [Requête](https://docs.aws.amazon.com/goto/boto3/dynamodb-2012-08-10/Query) dans la *référence d’API AWS du kit SDK pour Python (Boto3)*. ------ Pour obtenir la liste complète des guides de développement du AWS SDK et des exemples de code, consultez[Utilisation de DynamoDB avec un SDK AWS](sdk-general-information-section.md). Cette rubrique comprend également des informations sur le démarrage et sur les versions précédentes du kit SDK.