Hibernate Criteria Left排除了JOIN [英] Hibernate Criteria Left Excluding JOIN
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问题描述
我没有想法如何使用Hibernate Criteria做到这一点
SELECT *
FROM Table_A A
LEFT JOIN Table_B B
ON A.Key = B.Key
WHERE B.Key IS NULL
有Hibernate映射,如
@Entity
class A {
@Id
@Column(name =ID)
私人字符串ID;
... //字段
}
@实体
类B {
... //字段
@OneToOne(fetch = FetchType.EAGER)
@JoinColumn(name =A_ID,referencedColumnName =ID)
@Cascade(CascadeType.DETACH)
private A a ;
... //字段
}
需要获得所有未被B引用的A的列表
解决方案
以前没有尝试过,但是应该这样做:
select * from Table_A a
其中a不在(
从Table_B b中选择ba)
这当然是HQL
准则可能看起来像这样:
$ pre $ Det $ C $子$ a.ID))
.add(Restrictions.isNotNull(a.ID));
session.createCriteria(A.class)
.add(Property.forName(ID).InIn(subquery))
.list();
I have no ideas how to do it using Hibernate Criteria
SELECT *
FROM Table_A A
LEFT JOIN Table_B B
ON A.Key = B.Key
WHERE B.Key IS NULL
there is Hibernate mapping like
@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
}
So I need to get list of all A which are not referred by B
解决方案
Not tried it before, but something like this should work:
select * from Table_A a
where a not in (
select b.a from Table_B b )
This is of course in HQL
Criteria might look like this:
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();
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