SpecValueMapper.xml to jpa

把 SpecValueMapper.xml 中，下面的SQL转JPA，又是转不成功，JPQL报错。导航关系更不会配置。

老师，能不能加强一下JPA的初中高级用法讲解 ，最好把三阶段全部功能，转换为JPA方法讲一下。

<select id="getSpecKeyAndValueById" resultMap="SpecKeyAndValueResultMap">

        select v.id value_id, v.value spec_value, k.id key_id, k.name spec_key

        from spec_value as v

        left join spec_key as k on v.spec_id=k.id

        where v.id = #{valueId}

        and v.delete_time is null

        and k.id = #{keyId}

        and k.delete_time is null

        limit 1

    </select>

下面的JPQL，变异通不过，提示找不到SpecKey:

public interface SpecKeyRepository extends JpaRepository<SpecKey,Long> {

    @Query(" select new com.linCMS.model.SpecKeyValue(v.id , v.value, k.id, k.name)\n" +

            " from SpecValue  v\n" +

            "        left join Speckey  k on v.specId=k.id\n" +

            "        where v.id = :valueId\n" +

            "        and k.id = :keyId\n" )

    List<SpecKeyValue> getSpecKeyAndValueById(Long keyId, Long valueId);

}