“where exists” in Hibernate HQL

Question

How can I write a "not exists" query in HQL? I am trying to get an HQL not exists query which returns the same results as this Oracle SQL query:

Answer 1

Try this:

from School s where (select count(st) from Student st
  where st.school_id=s.id and st.status.id not in (0,1,2,3,4)) = 0

Answer 2

Your named query is not valid (school_id is not a property of the Student entity), which prevents the SessionFactory from being instantiated. You need to think object and associations, not columns. Try this instead:

from School as s
where not exists (
  from Student as st
  where st.school = s
  and st.status.id not in (0,1,2,3,4)
)

References

• Hibernate Core Reference Guide
  • 14.13. Subqueries