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我具有低于类LEFT OUTER在休眠JOIN继承
@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;
}
这里B类是延伸类A.试图如下查询
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
我得到一个错误,因为c_id在B中是未知列。虽然表B是没有其父表具有c_id列。我如何写一个查询来实现左外连接?
是的,C是不是B类的属性,但是它可以继承自A类而不发生。这是我的问题 –