Spring Data JPA中join的查询

Question

Select a.id,a.desc,b.desc from A a  left join B b on a.MEDIA_ID = b.ID

提前致谢

Answer 1

下面是一个使用SpringData连接查询的示例

public final static String FIND_WITH_DESC_QUERY = "SELECT a,b.desc as  bDescription " + 
                                                   "FROM A a LEFT JOIN a.descriptions b " +
                                                   "WHERE a.mediaID = :id";


@Query(FIND_WITH_DESC_QUERY)
public List<Media> findWithDescription(@Param("id") Long id);

注：

• 描述是实体A和B之间关系的映射。
• 假设@onetomany集descriptions()