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[英]DynamoDB Table Partition key and sort key are 1:1 - how to go about querying only using partition key?
[英]On Spring, how to query DynamoDB table using JPA and a composite key (Partition Key and Sort Key)?
我有一個使用 JPA 和 Spring Data DynamoDB 設置的 Spring 項目。 它工作正常。 我可以通過分區鍵和排序鍵(稱為DynamoDBHashKey
和DynamoDBRangeKey
)讀取它從 DynamoDB 表中獲取項目。
我的問題是我的存儲庫的設置方式是使用query
和scan
操作讀取表,而不是使用get-item
操作,這應該更有效。
這是我的實體:
import com.amazonaws.services.dynamodbv2.datamodeling.DynamoDBAttribute;
import com.amazonaws.services.dynamodbv2.datamodeling.DynamoDBHashKey;
import com.amazonaws.services.dynamodbv2.datamodeling.DynamoDBTable;
import lombok.AllArgsConstructor;
import lombok.Builder;
import lombok.Getter;
import lombok.NoArgsConstructor;
import lombok.Setter;
import org.springframework.data.annotation.Id;
@Getter
@Setter
@Builder
@NoArgsConstructor
@AllArgsConstructor
@DynamoDBTable(tableName = "my-entity-table")
public class MyEntity {
@Id
@DynamoDBHashKey
@DynamoDBAttribute(attributeName = "partition_key")
private String partitionKey;
@Id
@DynamoDBRangeKey
@DynamoDBAttribute(attributeName = "sort_key")
private String sortKey;
...
}
這是我的存儲庫:
import org.socialsignin.spring.data.dynamodb.repository.EnableScan;
import org.springframework.data.repository.CrudRepository;
import org.springframework.stereotype.Repository;
import java.util.List;
@EnableScan
@Repository
public interface MyEntityRepository extends CrudRepository<MyEntity, String> {
List<MyEntity> findByPartitionKeyAndSortKey(String partitionKey, String sortKey);
}
當我的表同時具有分區鍵和排序鍵時,如何配置我的實體和存儲庫以使用get-item
操作從表中讀取項目?
做了一些研究后,我偶然發現了這兩篇文章:
第一個解釋了如何在 Kotlin 中做我想做的事。 不錯,但這不是我正在尋找的。
第二個完美命中目標,基本上它說的是我需要為我的實體對象創建一個主鍵對象,如下所示:
import com.amazonaws.services.dynamodbv2.datamodeling.DynamoDBAttribute;
import com.amazonaws.services.dynamodbv2.datamodeling.DynamoDBDocument;
import com.amazonaws.services.dynamodbv2.datamodeling.DynamoDBHashKey;
import com.amazonaws.services.dynamodbv2.datamodeling.DynamoDBIgnore;
import com.amazonaws.services.dynamodbv2.datamodeling.DynamoDBRangeKey;
import com.amazonaws.services.dynamodbv2.datamodeling.DynamoDBTable;
import lombok.AllArgsConstructor;
import lombok.Builder;
import lombok.Getter;
import lombok.NoArgsConstructor;
import lombok.Setter;
import org.springframework.data.annotation.Id;
@Getter
@Setter
@Builder
@NoArgsConstructor
@AllArgsConstructor
@DynamoDBTable(tableName = "my-entity-table")
public class MyEntity {
@Id
@DynamoDBIgnore
private PrimaryKey primaryKey;
...
@DynamoDBHashKey
@DynamoDBAttribute(attributeName = "partition_key")
public String getPartitionKey() {
return primaryKey != null ? primaryKey.getPartitionKey() : null;
}
public void setPartitionKey(final String partitionKey) {
if (primaryKey == null) {
primaryKey = new PrimaryKey();
}
primaryKey.setPartitionKey(partitionKey);
}
@DynamoDBRangeKey
@DynamoDBAttribute(attributeName = "sort_key")
public String getSortKey() {
return primaryKey != null ? primaryKey.getSortKey() : null;
}
public void setSortKey(final String sortKey) {
if (primaryKey == null) {
primaryKey = new PrimaryKey();
}
primaryKey.setSortKey(sortKey);
}
@Getter
@Setter
@NoArgsConstructor
@AllArgsConstructor
@DynamoDBDocument
public static class PrimaryKey {
@DynamoDBHashKey
@DynamoDBAttribute(attributeName = "partition_key")
private String partitionKey;
@DynamoDBRangeKey
@DynamoDBAttribute(attributeName = "sort_key")
private String sortKey;
}
}
然后,我不需要在我的存儲庫類上創建任何自定義查詢方法:
@EnableScan
@Repository
public interface MyEntityRepository extends
CrudRepository<MyEntity, MyEntity.PrimaryKey> {
}
之后,只需使用 JPA 的CrudRepository
方法來獲取項目,就像這樣:
final MyEntity.PrimaryKey myEntityPK
= new MyEntity.PrimaryKey("partitionKey", "sortKey");
final MyEntity myEntity = myEntityRepository.findById(myEntityPK)
.orElseThrow(() -> ... );
為了驗證它實際上是在使用get-item
操作而不是scan
和query
操作,可以在以下類上放置幾個斷點(從spring-data-dynamodb-5.1.0
):
org.socialsignin.spring.data.dynamodb.core.DynamoDBTemplate
org.socialsignin.spring.data.dynamodb.repository.support.SimpleDynamoDBCrudRepository
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