Query Hash Key Only in DynamoDB Using Java (Guide w/ Code Examples)

A Query can omit the sort-key condition and retrieve every item in one partition-key value. Use the paginator to continue beyond the first response.

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)) {
                page.items().forEach(System.out::println);
            }
        }
    }
}

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