Question

我有一个DynamoDb表，我想使用主键和排序键从表中删除一个项目，

以下是我的代码 -

public Boolean deleteItem(String primaryKey, String sortKey) {
        DynamoDBUtil dynamoDBUtil = new DynamoDBUtil();
        AmazonDynamoDB dynamoDBClient = dynamoDBUtil.getDynamoDBClient();
        DynamoDB dynamoDB = new DynamoDB(dynamoDBClient);

        Table table = dynamoDB.getTable("demo_table");
        DeleteItemSpec deleteItemSpec = new DeleteItemSpec()
                .withPrimaryKey(new PrimaryKey("primaryKey", primaryKey))
                .withConditionExpression("primaryKey = :p_key and sortKey = :s_key")
                .withValueMap(new ValueMap()
                .withString(":p_key", primaryKey)
                .withString(":s_key", sortKey));

        table.deleteItem(deleteItemSpec);
        return true;
    }

我收到以下错误回复 -

Received error response: com.amazonaws.services.dynamodbv2.model.AmazonDynamoDBException: The provided key element does not match the schema (Service: AmazonDynamoDBv2; Status Code: 400; Error Code: ValidationException; Request ID: FHR7236SPHAJEANHBDKTO52Q2FVV4KQNSO5AEMVJF66Q9ASUAAJG)
Exception in thread "main" com.amazonaws.services.dynamodbv2.model.AmazonDynamoDBException: The provided key element does not match the schema (Service: AmazonDynamoDBv2; Status Code: 400; Error Code: ValidationException; Request ID: FHR7236SPHAJEANHBDKTO52Q2FVV4KQNSO5AEMVJF66Q9ASUAAJG)
    at com.amazonaws.http.AmazonHttpClient$RequestExecutor.handleErrorResponse(AmazonHttpClient.java:1588)
    at com.amazonaws.http.AmazonHttpClient$RequestExecutor.executeOneRequest(AmazonHttpClient.java:1258)
    at com.amazonaws.http.AmazonHttpClient$RequestExecutor.executeHelper(AmazonHttpClient.java:1030)
    at com.amazonaws.http.AmazonHttpClient$RequestExecutor.doExecute(AmazonHttpClient.java:742)
    at com.amazonaws.http.AmazonHttpClient$RequestExecutor.executeWithTimer(AmazonHttpClient.java:716)
    at com.amazonaws.http.AmazonHttpClient$RequestExecutor.execute(AmazonHttpClient.java:699)
    at com.amazonaws.http.AmazonHttpClient$RequestExecutor.access$500(AmazonHttpClient.java:667)
    at com.amazonaws.http.AmazonHttpClient$RequestExecutionBuilderImpl.execute(AmazonHttpClient.java:649)
    at com.amazonaws.http.AmazonHttpClient.execute(AmazonHttpClient.java:513)
    at com.amazonaws.services.dynamodbv2.AmazonDynamoDBClient.doInvoke(AmazonDynamoDBClient.java:2089)
    at com.amazonaws.services.dynamodbv2.AmazonDynamoDBClient.invoke(AmazonDynamoDBClient.java:2065)
    at com.amazonaws.services.dynamodbv2.AmazonDynamoDBClient.executeDeleteItem(AmazonDynamoDBClient.java:744)
    at com.amazonaws.services.dynamodbv2.AmazonDynamoDBClient.deleteItem(AmazonDynamoDBClient.java:720)
    at com.amazonaws.services.dynamodbv2.document.internal.DeleteItemImpl.doDeleteItem(DeleteItemImpl.java:96)
    at com.amazonaws.services.dynamodbv2.document.internal.DeleteItemImpl.deleteItem(DeleteItemImpl.java:75)
    at com.amazonaws.services.dynamodbv2.document.Table.deleteItem(Table.java:339)

我检查了双重检查，我的架构是正确的。

Answer 1

我认为您将分区（哈希）密钥与主键混淆。您的排序（范围）键是主键的一部分。因此，您需要将其作为主键的一部分提供。因此，不需要条件表达式。

主键=分区键+排序键

例如：

public Boolean deleteItem(String partitionKey, String sortKey) {
    DynamoDBUtil dynamoDBUtil = new DynamoDBUtil();
    AmazonDynamoDB dynamoDBClient = dynamoDBUtil.getDynamoDBClient();
    DynamoDB dynamoDB = new DynamoDB(dynamoDBClient);

    Table table = dynamoDB.getTable("demo_table");
    DeleteItemSpec deleteItemSpec = new DeleteItemSpec()
        .withPrimaryKey("partitionKey", partitionKey, "sortKey", sortKey);

    table.deleteItem(deleteItemSpec);
    return true;
}

AWS DynamoDb使用主键和排序键删除项目

1 个答案: