JPA中使用@Query注解多表联查

原生SQL：

select `user`.id, `user`.`name`,dept.name deptName,sum(sd.score) SumScore

from `user`

LEFT JOIN
score_detail sd
ON
`user`.id = sd.user_id

LEFT JOIN
department dept
ON
`user`.department_id = dept.id

GROUP BY `user`.`id` ORDER BY sum(sd.score);

 

通过查阅多方资料得知，

异常: org.hibernate.hql.ast.QuerySyntaxException: Path expected for join

 

HQL是面向对象的，因此join的条件是反映在对象的关系中的，因此，你在用join的时候，不管是left join仍是right join，都是

FROM DomainA a LEFT JOIN a.b b WHERE

或者

FROM DomainA a RIGHT JOIN a.b b WHERE

而不能直接是两个对象直接JOIN。

 

最终结果：

@Query("SELECT NEW com.ygsm.pojo.vo.SumScoreRankVO(u.id, u.name, d.name, SUM(s.score)) " + "FROM ScoreDetail s " + "RIGHT JOIN s.user u " + "RIGHT JOIN u.department d " + "WHERE s.createDate BETWEEN ?1 AND ?2 " + "GROUP BY u.id " + "ORDER BY SUM(s.score) DESC") List<SumScoreRankVO> findUserScoreRank(Date startDate, Date endDate);