Question

I have class structure as following

class ABC {
abcid;
name;
listOfXYZObjects;
}

class XYZ {
xyzid;
name;
}

Now I have configured above classes in hbm file. There is some data already stored in DB. I have abcId and xyzId with me and want to fetch only name fields of both classes in single HQL query.

Can any one guide me for above.

Answer 1

Assume your ABC is College and XYZ is Student. Using Criteria, we can get college name and student name as follows.

Criteria c = s.createCriteria(College.class,"clg");
c.createCriteria("students", "s");
c.add(Restrictions.eq("id",new Integer(1)));
c.add(Restrictions.eq("s.id", new Integer(1)));

ProjectionList properties = Projections.projectionList();
properties.add(Projections.property("name"));
properties.add(Projections.property("s.name"));
c.setProjection(properties);

List l=c.list();
Iterator it=l.iterator();
while(it.hasNext())
{
    Object ob[] = (Object[])it.next();
    System.out.println(ob[0]+"--------"+ob[1]);
}

Output:

Hibernate: select this_.name as y0_, s1_.name as y1_ from College1 this_ inner join Student1 s1_ on this_.id=s1_.colg_id where this_.id=? and s1_.id=?

SCASC College——–Student1