JPA 逻辑删除

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为了避免每次在查询的时候加上是否删除字段，做了一下封装。

@NoRepositoryBean
@RepositoryRestResource(exported = false)
public interface BaseRepository<T extends BaseEntity, IdT extends Long>
    extends JpaRepository<T, IdT> {

  @Query(
      value =
          "update #{#entityName} set deletedAt=current_timestamp where id = ?1 "
              + "and deletedAt is null")
  @Transactional
  @Modifying
  void delete(IdT id);

  @Override
  @Transactional
  default void delete(T entity) {
    delete((IdT) entity.getId());
  }

  @Transactional
  default void delete(Iterable<? extends T> entities) {
    entities.forEach(entitiy -> delete((IdT) entitiy.getId()));
  }

  @Override
  @Query(value = "update #{#entityName} set deletedAt=current_timestamp where deletedAt is null ")
  @Transactional
  @Modifying
  void deleteAll();

  @Query(
      value =
          "update #{#entityName} set deletedAt=current_timestamp where id in ?1 "
              + "and deletedAt is null ")
  @Transactional
  @Modifying
  void deleteInBatch(List<IdT> ids);
}

@NoRepositoryBean 使用了该注解的接口不会被单独创建实例，只会作为其他接口的父接口而被使用。
deletedAt 是否删除字段

@MappedSuperclass
@Data
public abstract class BaseEntity {

  private Timestamp deletedAt;

  public abstract Long getId();
}

@MappedSuperclass 通过这个注解，我们可以将该实体类当成基类实体，它不会隐射到数据库表，但继承它的子类实体在隐射时会自动扫描该基类实体的隐射属性，添加到子类实体的对应数据库表中。

@Data
@Entity
@Table(name = "indeed_api_keys")
@Where(clause = "deleted_at is null")
@NoArgsConstructor
public class IndeedApiKey extends BaseEntity implements Serializable {

  @Id
  @GeneratedValue(strategy = GenerationType.IDENTITY)
  private Long id;

  private String name;

  private String key;

  private static final long serialVersionUID = 1866497302444576352L;

}

实体继承BaseEntity,并加上 @Where(clause = “deleted_at is null”)

public interface EmailMessageRepository extends BaseRepository<EmailMessage, Long> {
  List<EmailMessage> findAllByApplicationId(Long applicationId);
  
@Query(
    value =
        "SELECT * FROM email_messages e WHERE e.deleted_at IS NULL AND "
            + "lower(?1)=lower(e.email_hash) ORDER BY e.created_at DESC",
    nativeQuery = true)
List<EmailMessage> findByEmailHash(String emailHash);
}

Repository继承BaseRepository

这样配置之后，若使用jpa默认的查询，就会自动加上 deleted_at is null的过滤条件。但当你重写jpa默认的查询机制，还是需要手动加上deleted_at is null的过滤条件。