How to get an intersect query using CriteriaQuery? - criteria-api

Question

Given :
#Entity
public class entity_details {
#Id
private int id;
#column(name ="entity_id")
private int entityId;
#column(name="att_id")
private int attId;
#column(name="att_value")
private string attVal;
I want to find a equivalent query to the below one
select entity_id from entity_details where att_id=15 and att_value='test'
intersect
select entity_id from entity_details where att_id=18 and att_value='test2';
using CriteriaQuery only.

Answer 1

It is a complex operation, you could try something like this:
CriteriaBuilder cb = entityManager.getCriteriaBuilder();
CriteriaQuery<Long> cq = cb.createQuery(Long.class);
Root<EntityDetails> root = cq.from(EntityDetails.class);
Subquery<EntityDetails> sq = cq.subquery(EntityDetails.class);
Root<EntityDetails> rootSQ = cq.from(EntityDetails.class);
sq.where(
cb.and(
cb.and(
cb.equal(rootSQ.get("attId"),18),
cb.equal(rootSQ.get("attValue"),"test2")
),
cb.equal(rootSQ.get("id"),root.get("id"))
)
);
cq.where(
cb.and(
cb.and(
cb.equal(root.get("attId"),15),
cb.equal(root.get("attValue"),"test")
),
cb.exist(sq)
)
);
cq.multiselect(root.get("entityId"));
What would generate the following Query:
select e1.entity_id from entity_details e1
where e1.att_id = 15 and e1.att_value = "test"
and exists(
select * from entity_details e2
where e2.att_id = 18 and e2.att_value = "test2"
and e1.id = e2.id
)