java - 避免 Spring 数据类中出现重复的 SQL 代码

Question

Spring data 有自己的注释“Query”，它将 SQL 查询与 Java 关联起来。它通常对存储库中的每个方法使用一个查询。

我的问题:Spring Data是否有办法编写一次查询并多次使用它？

例如，替换此代码

@Repository
public interface StuffRepository extends JpaRepository<Stuff, Integer>, JpaSpecificationExecutor<Stuff> {


    @Query(value = "SELECT s "
        + "FROM Stuff s "
        + "JOIN s.foo f"
        + "WHERE f.id = :id")
    Page<Stuff> findByFooId(@Param("id") String id,  Pageable pageable);

    @Query(value = "SELECT s "
        + "FROM Stuff s "
        + "JOIN s.foo f"
        + "WHERE f.id = :id")
    List<Stuff> findByFooId(@Param("id") String id);

    @Query(value = "SELECT s "
        + "FROM Stuff s "
        + "JOIN s.foo f"
        + "WHERE f.id = :id")
    Stuff findByFooIdFirst(@Param("id") String id);
}

像这样的事情

@Repository
public interface StuffRepository extends JpaRepository<Stuff, Integer>, JpaSpecificationExecutor<Stuff> {


    @Query(value = "SELECT s "     //create query findByFooId
        + "FROM Stuff s "
        + "JOIN s.foo f"
        + "WHERE f.id = :id",
        name = "findByFooId"
    )
    Page<Stuff> findByFooId(@Param("id") String id,  Pageable pageable);

    @Query(name = "findByFooId")   // link to query
    List<Stuff> findByFooId(@Param("id") String id);



    @Query(name = "findByFooId")   //link to query
    Stuff findByFooIdFirst(@Param("id") String id);
}

Answer 1

只需使用静态字符串进行查询即可

@Repository
public interface StuffRepository extends JpaRepository<Stuff, Integer>, JpaSpecificationExecutor<Stuff> {


String QUERY = "SELECT s "    
    + "FROM Stuff s "
    + "JOIN s.foo f"
    + "WHERE f.id = :id";

@Query(value = QUERY)   
List<Stuff> findByFooId(@Param("id") String id);


@Query(value= QUERY)   
Page<Stuff> findByFooId(@Param("id") String id,  Pageable pageable);