Hibernate继承中的LEFT OUTER JOIN

Question

我有以下课程

@Inheritance(strategy=InheritanceType.JOINED)
 Class A{
 private long a_id;
 private C C;

 }

 Class B extends A{
 private D d;
 }

 Class C{
 private long c_id;
 }

 Class D{
 private long d_id;
 private Set<B> bs;
 }

B类是A类的扩展。尝试按以下方式查询

Criterion criterion = Restrictions.and(Restrictions.eq(
                    "b.c", c_instance));

 Criteria c = session.createCriteria(D.class, "d")
 c.createAlias("bs", "b",JoinType.LEFT_OUTER_JOIN,criterion);
 c.createAlias("bs.c","c")

输出查询：

select d.d_id from D d left outer join B bs on d.d_id=bs.d_id and bs.c_id=2489 inner join A on bs.a_id=A.a_id inner join C A.c_id=C.c_id 

我收到错误消息，因为c_id是B中的unknonwn列。尽管表B没有其父表中的c_id列。 如何在此处编写查询以实现左外部联接？

Answer 1

我猜bs是B类的集合，您正在尝试从B类中获取c.createAlias（“ bs.c”，“ c”）