How do I rewrite this particular JPQL query with SELECT MAX() to CriteriaQuery?

Question

I am quite new to JPA and I have encountered a problem with understanding one particular query. I have rewritten in to the CriteriaQuery but the result and the query translated to SQL is not correct.

Background situation: I have a table of store transaction (moves) and the current amount in the store is defined as a sum of all changes. Now I want to select and display the last moves as they also contain an information about the resulting amount on store.

So, this is the query in JPQL:

SELECT m FROM move m WHERE m.id = (
  SELECT MAX(o.id) FROM move o WHERE (o.item = m.item AND m.cell.store = :s)

I tried to rewrite it to the following CriteriaQuery:

CriteriaBuilder builder = model.getCriteriaBuilder();
CriteriaQuery<Move> query = builder.createQuery(Move.class);
Root<Move> root = query.from(Move.class);

Subquery<Long> subquery = query.subquery(Long.class);
Root<Move> subroot = subquery.from(Move.class);
subquery.select(builder.max(subroot.get("id").as(Long.class)));

subquery.where(builder.and(
    builder.equal(
        subroot.get("item").get("id"),
        root.get("item").get("id")),
    builder.equal(
        subroot.get("cell").get("store").as(Store.class),
        store)));

Expression<Boolean> where = builder.equal(
    root.get("id"),
    subquery);

query.where(where);

return model.getList(query);

The incorrect SQL query produced is following:

SELECT t0.id, (...) FROM move t0 WHERE (t0.id = (
  SELECT MAX(t1.id) FROM item t3, item t2, move t1 
  WHERE (((t2.id = t3.id) AND 
        (t1.cell_store = ?)) AND 
        ((t2.id = t1.item_ref) AND 
        (t3.id = t0.item_ref))))
)

I do not understand why there is a double cross join in the subquery. Thank you for helping!

How do I rewrite this particular JPQL query with SELECT MAX() to CriteriaQuery?

0 Answers0