Java Hibernate Criteria returning only one entity fields

Question

i have a simple Criteria which is used by get the school of a student which i have the ID i need only the school not the student i have a simple coding like

public School loadSchool(Integer studentID) { final Session session = getHibernateTemplate().getSessionFactory().openSession(); final Criteria like = session.createCriteria(Student.class) .add(idEq(studentID)) .setFetchMode("School",FetchMode.JOIN); final School retValue = ((Student)like.uniqueResult()).getSchool(); session.close(); return retValue; }

as you can see i retrieve the Student and the School as well i need only the School my question are

1). there is a way other than setProjections() that i could extract[retrieve from the DB] only the School fields not the Student fields because are to many fields and is a kind annoying listing all the fields in setProjection and affects performance something like

setProjectionOnlyPropertiesForClass(School.class).

2). there is any workaround.

thanks a lot.

isnot2bad · Accepted Answer · 2013-09-24 13:42:51Z

The problem is that you're querying Student objects instead of School objects! The corresponding HQL query is:

select student from Student student join student.school where student.id=:studentId

Instead, you should query for School objects:

select school from School school, Student student where student.school = school and student.id=:studentId

(Maybe you should use HQL instead of criteria queries for that - they are simpler to write and understand).

Collectives™ on Stack Overflow

Java Hibernate Criteria returning only one entity fields

1 Answer 1

Comments

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Related