Java 左侧休眠条件排除联接
我不知道如何使用Hibernate标准来实现它Java 左侧休眠条件排除联接,java,hibernate,join,hibernate-criteria,Java,Hibernate,Join,Hibernate Criteria,我不知道如何使用Hibernate标准来实现它 SELECT * FROM Table_A A LEFT JOIN Table_B B ON A.Key = B.Key WHERE B.Key IS NULL 有像这样的Hibernate映射 @Entity class A{ @Id @Column(name = "ID") private String ID; ... // fields } @Entity class B{ ... // fi
SELECT *
FROM Table_A A
LEFT JOIN Table_B B
ON A.Key = B.Key
WHERE B.Key IS NULL
有像这样的Hibernate映射
@Entity
class A{
@Id
@Column(name = "ID")
private String ID;
... // fields
}
@Entity
class B{
... // fields
@OneToOne(fetch = FetchType.EAGER)
@JoinColumn(name = "A_ID", referencedColumnName = "ID")
@Cascade(CascadeType.DETACH)
private A a;
... // fields
}
所以我需要得到所有A的列表,这些A没有被B引用,以前没有尝试过,但类似的东西应该可以工作:
select * from Table_A a
where a not in (
select b.a from Table_B b )
这当然是在HQL中
标准可能如下所示:
DetachedCriteria subquery = DetachedCriteria.forClass(B.class)
.setProjection( Property.forName("a.ID") )
.add(Restrictions.isNotNull("a.ID"));
session.createCriteria(A.class)
.add ( Property.forName("ID").notIn(subquery) )
.list();
只有一件事。DetachedCriterias子查询=DetachedCriterias.forClass(B.class).setProjection(Property.forName(“a.ID”)).add(Restrictions.isNotNull(“a.ID”);