I'm trying to run a query that checks if some conditions are true and returns a simple boolean result as output. What makes it slightly tricky is that one of the conditions is to test for whether no results are returned for a set of criteria.
I'm currently using JPA-2.0 with hibernate as my provider, backed by MySQL. I have gotten an example query working fine in MySQL, but when trying to get it running in JPQL it flops. The MySQL query looks a bit like this:
Select exists(Select statement with criteria)
or not exists(Select statement with criteria);
I also got the same output using CASE, but as JPQL doesn't support that statement.
Anyways, when I try to use a similar query in JPQL I get the error:
"unexpected end of subtree"
which from my understanding means that something is missing in the query. Does anyone have any idea how to fix it?
This answer is obsolete. Yes, it is possible. Please refer to the correct answer from Rene Link
No, it is not possible.
Refer to the JPQL BNF documentation from oracle.
simple_cond_expression ::= comparison_expression | between_expression | like_expression | in_expression | null_comparison_expression | empty_collection_comparison_expression | collection_member_expression | exists_expression
exists_expression ::= [NOT] EXISTS(subquery)