Delete by Hashkey Using DynamoDB Mapper (Guide w/ Code Examples)

Deleting a partition-key value is not a single API operation when the table has a sort key. Query the item collection, then delete each complete key.

DynamoDBMapper belongs to AWS SDK for Java 1.x and cannot be constructed with a 2.x DynamoDbClient. The example below shows the SDK 2.x low-level equivalent. For mapped domain objects, use the DynamoDB Enhanced Client.

This example uses Java 17+ and the software.amazon.awssdk:dynamodb SDK 2.x dependency. Configure an AWS Region and credentials through your usual AWS profile or runtime role. The Orders table has String keys pk and sk; adapt the table and keys to your schema.

import java.util.*;
import software.amazon.awssdk.services.dynamodb.DynamoDbClient;
import software.amazon.awssdk.services.dynamodb.model.*;

public class Example {
    static AttributeValue s(String value) { return AttributeValue.builder().s(value).build(); }
    static Map<String, AttributeValue> key(String order) {
        return Map.of("pk", s("CUSTOMER#123"), "sk", s(order));
    }

    public static void main(String[] args) throws InterruptedException {
        try (DynamoDbClient ddb = DynamoDbClient.create()) {
            QueryRequest request = QueryRequest.builder().tableName("Orders")
                .keyConditionExpression("#pk = :pk")
                .expressionAttributeNames(Map.of("#pk", "pk"))
                .expressionAttributeValues(Map.of(":pk", s("CUSTOMER#123"))).build();
            for (QueryResponse page : ddb.queryPaginator(request)) {
                for (Map<String, AttributeValue> item : page.items()) {
                    ddb.deleteItem(DeleteItemRequest.builder().tableName("Orders")
                        .key(Map.of("pk", item.get("pk"), "sk", item.get("sk"))).build());
                }
            }
        }
    }
}

Stop concurrent writes for a maintenance purge. The query and deletes do not form one atomic operation, and new items may appear during the job.

Reference: AWS DeleteItem API. For related access patterns, see DynamoDB query examples.