Hibernate criteria query on different properties of different objects
Suppose I have classes like:
class A {
B getB();
C getC();
}
class B {
String getFoo();
}
class C {
int getBar();
}
and I want to filter criteria on A, two filters on different subclass properties, like:
Criteria criteriaA = session.createCriteria(A.class);
Criteria criteriaB = criteriaA.createCriteria("b").add开发者_Python百科(Restrictions.eq("foo", "Something"));
Criteria criteriaC = criteriaA.createCriteria("c").add(Restrictions.eq("bar", 0));
What I want to do is combine criteriaB and criteriaC using an "or" clause, something like:
//this does not work
criteriaA.add(Restrictions.disjunction().add(criteriaB).add(criteriaC));
How can I accomplish this? I am stumbling a little over the API here.
Use aliases instead of nested criteria:
Criteria criteria = session.createCriteria(A.class)
.createAlias("b", "b_alias")
.createAlias("c", "c_alias")
.add(Restrictions.disjunction()
.add(Restrictions.eq("b_alias.foo", "Something"))
.add(Restrictions.eq("c_alias.bar", "0"))
);
You only need to create one criteria object like so.
Criteria criteria = session.createCriteria(A.class);
criteria.add(Restriction.disjunction()
.add(Restriction.eq("b.foo", "something"))
.add(Restriction.eq("c.bar", 0)));
In case someone else finds it useful, I found a more complicated answer to the problem which appears to be allowed by the API, though I did not get to test it before ChssPly posted his (simpler) solution:
DetachedCriteria bValues = DetachedCriteria.forClass(A.class);
bValues.createCriteria("b").add(Restrictions.eq("foo", "something"));
DetachedCriteria cValues = DetachedCriteria.forClass(A.class);
cValues.createCriteria("c").add(Restrictions.eq("bar", 0));
Restrictions.or(Subqueries.in("id", bValues), Subqueries.in("id", cValues));
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