Question

左连接不是反复空值

当A.B.name喜欢＆＃34;％pac％＆＃34;时，我需要获得所有记录A.或A.C.name喜欢＆＃34;％pac％＆＃34;

  Class<T> entityClass = (Class<T>) A.class;
    PathBuilder<T> entity = new PathBuilder<T>(entityClass, "entity");

    EntityManager entityManager = entityManagerProvider
            .getEntityManager(entity.getType());

    JPAQuery query = new JPAQuery(entityManager);
    query = query.from(entity);

    PathBuilder<?> associationPathB = entity.get("B");
    query = query.leftJoin(associationPathB).fetch();

    PathBuilder<?> associationPathC = entity.get("C");
    query = query.leftJoin(associationPathC).fetch();


    BooleanBuilder baseSearch = new BooleanBuilder();
    baseSearch.and(associationPathB.getString("name").lower().like("%pac%"))
            .or(associationPathC.getString("name").lower().like("%pac%"));

    query.where(baseSearch.getValue());

    long count = query.count();

生成的查询是

select entity from A entity 
left join fetch entity.B 
left join fetch entity.C 
where lower(entity.B.name) like ?1 escape '!' 
or lower(entity.C.name) like ?2 escape '!'

count只返回2条记录，但我有10条A类记录，其中B.name喜欢=＆＃39; pac＆＃39;。

C列中只有2条记录不为空，但这是OR条件

的连接

为什么不退回10条记录？

如果我在DB中执行查询，则返回10个寄存器

select * from A entA
left join B entB on entB.id = entA.entB
left join C entC on entC.id = entA.entC
where entB.name  like '%pac%' OR
entC.name like '%pac%'

在jpa mysema查询中左连接空值

0 个答案: