Hibernate Criteria:查找实体,如果其子项的子项具有特定属性

Question

我需要编写一个Criteria(或hql)来通过子实体的子属性查找父实体.这是我的实体:

// The top level parent class
public class A {
    private Long id;
    private String someProperty;
    private B b;
    // and some other attributes...
}

// The second level parent class :)
public class B {
    private Long id;
    private List<C> cList;
    // and some other attributes...
}

public class C {
    private Long id;
    private B b;
    private List<D> dList;
    // Other attributes..
}

public class D {
    private Long id;
    private C c;
    private String importantAttribute;
    // Other attributes..
}

问题如下.A如果任何D记录具有条件importantAttribute =="something"并且如果A具有条件someProperty =="somethingelse",我想获取记录列表.

我怎么能为此编写一个hibernate标准？我所能写的所有内容如下:

Criteria criteria = getSession().createCriteria(A.class, "a");
criteria.add(Restrictions.eq("a.someProperty", "somethingelse");

DetachedCriteria sub = DetachedCriteria.forClass(D.class, "d");
sub.add(Restrictions.eq("d.importantAttribute", "something"));
sub.setProjection(Projections.property("id"));

然后我放弃了.

Answer 1

试试这个

Criteria criteria = getSession().createCriteria(A.class, "a");
criteria.createAlias("a.b", "b");
criteria.createAlias("b.cList", "c");
criteria.createAlias("c.dList", "d");
criteria.add(Restrictions.eq("a.someProperty", "somethingelse");
criteria.add(Restrictions.eq("d.importantAttribute", "something");