예: AWS SDK for .NET 하위 수준 API를 사용하는 로컬 보조 인덱스 - Amazon DynamoDB

예: AWS SDK for .NET 하위 수준 API를 사용하는 로컬 보조 인덱스

다음 C# 코드 예제는 Amazon DynamoDB에서 로컬 보조 인덱스로 작업하는 방법을 보여 줍니다. 예를 들어 파티션 키가 CustomerId이고 정렬 키가 OrderId인 CustomerOrders라는 테이블을 만들 수 있습니다. 이 테이블에는 두 개의 로컬 보조 인덱스가 있습니다.

  • OrderCreationDateIndex - 정렬 키는 OrderCreationDate이며 다음 속성이 인덱스로 프로젝션됩니다.

    • ProductCategory

    • ProductName

    • OrderStatus

    • ShipmentTrackingId

  • IsOpenIndex - 정렬 키는 IsOpen이며 모든 테이블 속성이 인덱스로 프로젝션됩니다.

CustomerOrders 테이블이 생성되면 프로그램에서 고객 주문을 나타내는 데이터와 함께 테이블을 로드합니다. 그런 다음 로컬 보조 인덱스를 사용하여 데이터를 쿼리합니다. 마지막으로 프로그램에서 CustomerOrders 테이블을 삭제합니다.

다음 예제를 테스트하기 위한 단계별 지침은 .NET 코드 예시 단원을 참조하세요.

예 
using System;
using System.Collections.Generic;
using System.Linq;
using Amazon.DynamoDBv2;
using Amazon.DynamoDBv2.DataModel;
using Amazon.DynamoDBv2.DocumentModel;
using Amazon.DynamoDBv2.Model;
using Amazon.Runtime;
using Amazon.SecurityToken;

namespace com.amazonaws.codesamples
{
    class LowLevelLocalSecondaryIndexExample
    {
        private static AmazonDynamoDBClient client = new AmazonDynamoDBClient();
        private static string tableName = "CustomerOrders";

        static void Main(string[] args)
        {
            try
            {
                CreateTable();
                LoadData();

                Query(null);
                Query("IsOpenIndex");
                Query("OrderCreationDateIndex");

                DeleteTable(tableName);

                Console.WriteLine("To continue, press Enter");
                Console.ReadLine();
            }
            catch (AmazonDynamoDBException e) { Console.WriteLine(e.Message); }
            catch (AmazonServiceException e) { Console.WriteLine(e.Message); }
            catch (Exception e) { Console.WriteLine(e.Message); }
        }

        private static void CreateTable()
        {
            var createTableRequest =
                new CreateTableRequest()
                {
                    TableName = tableName,
                    ProvisionedThroughput =
                    new ProvisionedThroughput()
                    {
                        ReadCapacityUnits = (long)1,
                        WriteCapacityUnits = (long)1
                    }
                };

            var attributeDefinitions = new List<AttributeDefinition>()
        {
            // Attribute definitions for table primary key
            { new AttributeDefinition() {
                  AttributeName = "CustomerId", AttributeType = "S"
              } },
            { new AttributeDefinition() {
                  AttributeName = "OrderId", AttributeType = "N"
              } },
            // Attribute definitions for index primary key
            { new AttributeDefinition() {
                  AttributeName = "OrderCreationDate", AttributeType = "N"
              } },
            { new AttributeDefinition() {
                  AttributeName = "IsOpen", AttributeType = "N"
              }}
        };

            createTableRequest.AttributeDefinitions = attributeDefinitions;

            // Key schema for table
            var tableKeySchema = new List<KeySchemaElement>()
        {
            { new KeySchemaElement() {
                  AttributeName = "CustomerId", KeyType = "HASH"
              } },                                                  //Partition key
            { new KeySchemaElement() {
                  AttributeName = "OrderId", KeyType = "RANGE"
              } }                                                //Sort key
        };

            createTableRequest.KeySchema = tableKeySchema;

            var localSecondaryIndexes = new List<LocalSecondaryIndex>();

            // OrderCreationDateIndex
            LocalSecondaryIndex orderCreationDateIndex = new LocalSecondaryIndex()
            {
                IndexName = "OrderCreationDateIndex"
            };

            // Key schema for OrderCreationDateIndex
            var indexKeySchema = new List<KeySchemaElement>()
        {
            { new KeySchemaElement() {
                  AttributeName = "CustomerId", KeyType = "HASH"
              } },                                                    //Partition key
            { new KeySchemaElement() {
                  AttributeName = "OrderCreationDate", KeyType = "RANGE"
              } }                                                            //Sort key
        };

            orderCreationDateIndex.KeySchema = indexKeySchema;

            // Projection (with list of projected attributes) for
            // OrderCreationDateIndex
            var projection = new Projection()
            {
                ProjectionType = "INCLUDE"
            };

            var nonKeyAttributes = new List<string>()
        {
            "ProductCategory",
            "ProductName"
        };
            projection.NonKeyAttributes = nonKeyAttributes;

            orderCreationDateIndex.Projection = projection;

            localSecondaryIndexes.Add(orderCreationDateIndex);

            // IsOpenIndex
            LocalSecondaryIndex isOpenIndex
                = new LocalSecondaryIndex()
                {
                    IndexName = "IsOpenIndex"
                };

            // Key schema for IsOpenIndex
            indexKeySchema = new List<KeySchemaElement>()
        {
            { new KeySchemaElement() {
                  AttributeName = "CustomerId", KeyType = "HASH"
              }},                                                     //Partition key
            { new KeySchemaElement() {
                  AttributeName = "IsOpen", KeyType = "RANGE"
              }}                                                  //Sort key
        };

            // Projection (all attributes) for IsOpenIndex
            projection = new Projection()
            {
                ProjectionType = "ALL"
            };

            isOpenIndex.KeySchema = indexKeySchema;
            isOpenIndex.Projection = projection;

            localSecondaryIndexes.Add(isOpenIndex);

            // Add index definitions to CreateTable request
            createTableRequest.LocalSecondaryIndexes = localSecondaryIndexes;

            Console.WriteLine("Creating table " + tableName + "...");
            client.CreateTable(createTableRequest);
            WaitUntilTableReady(tableName);
        }

        public static void Query(string indexName)
        {
            Console.WriteLine("\n***********************************************************\n");
            Console.WriteLine("Querying table " + tableName + "...");

            QueryRequest queryRequest = new QueryRequest()
            {
                TableName = tableName,
                ConsistentRead = true,
                ScanIndexForward = true,
                ReturnConsumedCapacity = "TOTAL"
            };


            String keyConditionExpression = "CustomerId = :v_customerId";
            Dictionary<string, AttributeValue> expressionAttributeValues = new Dictionary<string, AttributeValue> {
            {":v_customerId", new AttributeValue {
                 S = "bob@example.com"
             }}
        };


            if (indexName == "IsOpenIndex")
            {
                Console.WriteLine("\nUsing index: '" + indexName
                          + "': Bob's orders that are open.");
                Console.WriteLine("Only a user-specified list of attributes are returned\n");
                queryRequest.IndexName = indexName;

                keyConditionExpression += " and IsOpen = :v_isOpen";
                expressionAttributeValues.Add(":v_isOpen", new AttributeValue
                {
                    N = "1"
                });

                // ProjectionExpression
                queryRequest.ProjectionExpression = "OrderCreationDate, ProductCategory, ProductName, OrderStatus";
            }
            else if (indexName == "OrderCreationDateIndex")
            {
                Console.WriteLine("\nUsing index: '" + indexName
                          + "': Bob's orders that were placed after 01/31/2013.");
                Console.WriteLine("Only the projected attributes are returned\n");
                queryRequest.IndexName = indexName;

                keyConditionExpression += " and OrderCreationDate > :v_Date";
                expressionAttributeValues.Add(":v_Date", new AttributeValue
                {
                    N = "20130131"
                });

                // Select
                queryRequest.Select = "ALL_PROJECTED_ATTRIBUTES";
            }
            else
            {
                Console.WriteLine("\nNo index: All of Bob's orders, by OrderId:\n");
            }
            queryRequest.KeyConditionExpression = keyConditionExpression;
            queryRequest.ExpressionAttributeValues = expressionAttributeValues;

            var result = client.Query(queryRequest);
            var items = result.Items;
            foreach (var currentItem in items)
            {
                foreach (string attr in currentItem.Keys)
                {
                    if (attr == "OrderId" || attr == "IsOpen"
                        || attr == "OrderCreationDate")
                    {
                        Console.WriteLine(attr + "---> " + currentItem[attr].N);
                    }
                    else
                    {
                        Console.WriteLine(attr + "---> " + currentItem[attr].S);
                    }
                }
                Console.WriteLine();
            }
            Console.WriteLine("\nConsumed capacity: " + result.ConsumedCapacity.CapacityUnits + "\n");
        }

        private static void DeleteTable(string tableName)
        {
            Console.WriteLine("Deleting table " + tableName + "...");
            client.DeleteTable(new DeleteTableRequest()
            {
                TableName = tableName
            });
            WaitForTableToBeDeleted(tableName);
        }

        public static void LoadData()
        {
            Console.WriteLine("Loading data into table " + tableName + "...");

            Dictionary<string, AttributeValue> item = new Dictionary<string, AttributeValue>();

            item["CustomerId"] = new AttributeValue
            {
                S = "alice@example.com"
            };
            item["OrderId"] = new AttributeValue
            {
                N = "1"
            };
            item["IsOpen"] = new AttributeValue
            {
                N = "1"
            };
            item["OrderCreationDate"] = new AttributeValue
            {
                N = "20130101"
            };
            item["ProductCategory"] = new AttributeValue
            {
                S = "Book"
            };
            item["ProductName"] = new AttributeValue
            {
                S = "The Great Outdoors"
            };
            item["OrderStatus"] = new AttributeValue
            {
                S = "PACKING ITEMS"
            };
            /* no ShipmentTrackingId attribute */
            PutItemRequest putItemRequest = new PutItemRequest
            {
                TableName = tableName,
                Item = item,
                ReturnItemCollectionMetrics = "SIZE"
            };
            client.PutItem(putItemRequest);

            item = new Dictionary<string, AttributeValue>();
            item["CustomerId"] = new AttributeValue
            {
                S = "alice@example.com"
            };
            item["OrderId"] = new AttributeValue
            {
                N = "2"
            };
            item["IsOpen"] = new AttributeValue
            {
                N = "1"
            };
            item["OrderCreationDate"] = new AttributeValue
            {
                N = "20130221"
            };
            item["ProductCategory"] = new AttributeValue
            {
                S = "Bike"
            };
            item["ProductName"] = new AttributeValue
            {
                S = "Super Mountain"
            };
            item["OrderStatus"] = new AttributeValue
            {
                S = "ORDER RECEIVED"
            };
            /* no ShipmentTrackingId attribute */
            putItemRequest = new PutItemRequest
            {
                TableName = tableName,
                Item = item,
                ReturnItemCollectionMetrics = "SIZE"
            };
            client.PutItem(putItemRequest);

            item = new Dictionary<string, AttributeValue>();
            item["CustomerId"] = new AttributeValue
            {
                S = "alice@example.com"
            };
            item["OrderId"] = new AttributeValue
            {
                N = "3"
            };
            /* no IsOpen attribute */
            item["OrderCreationDate"] = new AttributeValue
            {
                N = "20130304"
            };
            item["ProductCategory"] = new AttributeValue
            {
                S = "Music"
            };
            item["ProductName"] = new AttributeValue
            {
                S = "A Quiet Interlude"
            };
            item["OrderStatus"] = new AttributeValue
            {
                S = "IN TRANSIT"
            };
            item["ShipmentTrackingId"] = new AttributeValue
            {
                S = "176493"
            };
            putItemRequest = new PutItemRequest
            {
                TableName = tableName,
                Item = item,
                ReturnItemCollectionMetrics = "SIZE"
            };
            client.PutItem(putItemRequest);

            item = new Dictionary<string, AttributeValue>();
            item["CustomerId"] = new AttributeValue
            {
                S = "bob@example.com"
            };
            item["OrderId"] = new AttributeValue
            {
                N = "1"
            };
            /* no IsOpen attribute */
            item["OrderCreationDate"] = new AttributeValue
            {
                N = "20130111"
            };
            item["ProductCategory"] = new AttributeValue
            {
                S = "Movie"
            };
            item["ProductName"] = new AttributeValue
            {
                S = "Calm Before The Storm"
            };
            item["OrderStatus"] = new AttributeValue
            {
                S = "SHIPPING DELAY"
            };
            item["ShipmentTrackingId"] = new AttributeValue
            {
                S = "859323"
            };
            putItemRequest = new PutItemRequest
            {
                TableName = tableName,
                Item = item,
                ReturnItemCollectionMetrics = "SIZE"
            };
            client.PutItem(putItemRequest);

            item = new Dictionary<string, AttributeValue>();
            item["CustomerId"] = new AttributeValue
            {
                S = "bob@example.com"
            };
            item["OrderId"] = new AttributeValue
            {
                N = "2"
            };
            /* no IsOpen attribute */
            item["OrderCreationDate"] = new AttributeValue
            {
                N = "20130124"
            };
            item["ProductCategory"] = new AttributeValue
            {
                S = "Music"
            };
            item["ProductName"] = new AttributeValue
            {
                S = "E-Z Listening"
            };
            item["OrderStatus"] = new AttributeValue
            {
                S = "DELIVERED"
            };
            item["ShipmentTrackingId"] = new AttributeValue
            {
                S = "756943"
            };
            putItemRequest = new PutItemRequest
            {
                TableName = tableName,
                Item = item,
                ReturnItemCollectionMetrics = "SIZE"
            };
            client.PutItem(putItemRequest);

            item = new Dictionary<string, AttributeValue>();
            item["CustomerId"] = new AttributeValue
            {
                S = "bob@example.com"
            };
            item["OrderId"] = new AttributeValue
            {
                N = "3"
            };
            /* no IsOpen attribute */
            item["OrderCreationDate"] = new AttributeValue
            {
                N = "20130221"
            };
            item["ProductCategory"] = new AttributeValue
            {
                S = "Music"
            };
            item["ProductName"] = new AttributeValue
            {
                S = "Symphony 9"
            };
            item["OrderStatus"] = new AttributeValue
            {
                S = "DELIVERED"
            };
            item["ShipmentTrackingId"] = new AttributeValue
            {
                S = "645193"
            };
            putItemRequest = new PutItemRequest
            {
                TableName = tableName,
                Item = item,
                ReturnItemCollectionMetrics = "SIZE"
            };
            client.PutItem(putItemRequest);

            item = new Dictionary<string, AttributeValue>();
            item["CustomerId"] = new AttributeValue
            {
                S = "bob@example.com"
            };
            item["OrderId"] = new AttributeValue
            {
                N = "4"
            };
            item["IsOpen"] = new AttributeValue
            {
                N = "1"
            };
            item["OrderCreationDate"] = new AttributeValue
            {
                N = "20130222"
            };
            item["ProductCategory"] = new AttributeValue
            {
                S = "Hardware"
            };
            item["ProductName"] = new AttributeValue
            {
                S = "Extra Heavy Hammer"
            };
            item["OrderStatus"] = new AttributeValue
            {
                S = "PACKING ITEMS"
            };
            /* no ShipmentTrackingId attribute */
            putItemRequest = new PutItemRequest
            {
                TableName = tableName,
                Item = item,
                ReturnItemCollectionMetrics = "SIZE"
            };
            client.PutItem(putItemRequest);

            item = new Dictionary<string, AttributeValue>();
            item["CustomerId"] = new AttributeValue
            {
                S = "bob@example.com"
            };
            item["OrderId"] = new AttributeValue
            {
                N = "5"
            };
            /* no IsOpen attribute */
            item["OrderCreationDate"] = new AttributeValue
            {
                N = "20130309"
            };
            item["ProductCategory"] = new AttributeValue
            {
                S = "Book"
            };
            item["ProductName"] = new AttributeValue
            {
                S = "How To Cook"
            };
            item["OrderStatus"] = new AttributeValue
            {
                S = "IN TRANSIT"
            };
            item["ShipmentTrackingId"] = new AttributeValue
            {
                S = "440185"
            };
            putItemRequest = new PutItemRequest
            {
                TableName = tableName,
                Item = item,
                ReturnItemCollectionMetrics = "SIZE"
            };
            client.PutItem(putItemRequest);

            item = new Dictionary<string, AttributeValue>();
            item["CustomerId"] = new AttributeValue
            {
                S = "bob@example.com"
            };
            item["OrderId"] = new AttributeValue
            {
                N = "6"
            };
            /* no IsOpen attribute */
            item["OrderCreationDate"] = new AttributeValue
            {
                N = "20130318"
            };
            item["ProductCategory"] = new AttributeValue
            {
                S = "Luggage"
            };
            item["ProductName"] = new AttributeValue
            {
                S = "Really Big Suitcase"
            };
            item["OrderStatus"] = new AttributeValue
            {
                S = "DELIVERED"
            };
            item["ShipmentTrackingId"] = new AttributeValue
            {
                S = "893927"
            };
            putItemRequest = new PutItemRequest
            {
                TableName = tableName,
                Item = item,
                ReturnItemCollectionMetrics = "SIZE"
            };
            client.PutItem(putItemRequest);

            item = new Dictionary<string, AttributeValue>();
            item["CustomerId"] = new AttributeValue
            {
                S = "bob@example.com"
            };
            item["OrderId"] = new AttributeValue
            {
                N = "7"
            };
            /* no IsOpen attribute */
            item["OrderCreationDate"] = new AttributeValue
            {
                N = "20130324"
            };
            item["ProductCategory"] = new AttributeValue
            {
                S = "Golf"
            };
            item["ProductName"] = new AttributeValue
            {
                S = "PGA Pro II"
            };
            item["OrderStatus"] = new AttributeValue
            {
                S = "OUT FOR DELIVERY"
            };
            item["ShipmentTrackingId"] = new AttributeValue
            {
                S = "383283"
            };
            putItemRequest = new PutItemRequest
            {
                TableName = tableName,
                Item = item,
                ReturnItemCollectionMetrics = "SIZE"
            };
            client.PutItem(putItemRequest);
        }

        private static void WaitUntilTableReady(string tableName)
        {
            string status = null;
            // Let us wait until table is created. Call DescribeTable.
            do
            {
                System.Threading.Thread.Sleep(5000); // Wait 5 seconds.
                try
                {
                    var res = client.DescribeTable(new DescribeTableRequest
                    {
                        TableName = tableName
                    });

                    Console.WriteLine("Table name: {0}, status: {1}",
                              res.Table.TableName,
                              res.Table.TableStatus);
                    status = res.Table.TableStatus;
                }
                catch (ResourceNotFoundException)
                {
                    // DescribeTable is eventually consistent. So you might
                    // get resource not found. So we handle the potential exception.
                }
            } while (status != "ACTIVE");
        }

        private static void WaitForTableToBeDeleted(string tableName)
        {
            bool tablePresent = true;

            while (tablePresent)
            {
                System.Threading.Thread.Sleep(5000); // Wait 5 seconds.
                try
                {
                    var res = client.DescribeTable(new DescribeTableRequest
                    {
                        TableName = tableName
                    });

                    Console.WriteLine("Table name: {0}, status: {1}",
                              res.Table.TableName,
                              res.Table.TableStatus);
                }
                catch (ResourceNotFoundException)
                {
                    tablePresent = false;
                }
            }
        }
    }
}