hibernate - Example Queries in Hibernate

Question

I have trying to understand how does an Example query in Hibernate works.

deptId is the primary key of the departments table.

I tried this code initially:

Dept department = new Dept();
        department.setDeptId(3);
        //department.setDeptName("ABCD");
        Criteria criteria = session.createCriteria(Dept.class).add(Example.create(department));

Executing this code, the results are not getting filtered w.r.t the rows having deptId = 3 i.e, the SQL Query is equivalent to selecting all records from Dept table where 1 = 1.

But if i consider this code:

Dept department = new Dept();
        //department.setDeptId(3);
        department.setDeptName("ABCD");
        Criteria criteria = session.createCriteria(Dept.class).add(Example.create(department));

The results are getting filtered w.r.t the deptName i.e. ABCD

Please inform why is the Example query behaving like this.

Answer 1

From the documentation , query by example (QBE) will ignore primary key.

For the simple primary key , if you know the value of the PK , you could use load() or get()instead.

For the composite primary key , I agree that support of primary key in QBE is necessary . However , this request is still unresolved.