JPQL -Collection Member Expressions -type mismatch

Question

I'm trying to run the query below but I get an error
Caused by: java.lang.IllegalArgumentException: You have attempted to set
a value of type class java.lang.String for parameter contid with expected type
of class mmis.entity.Contract from
query string SELECT c FROM Consultant c WHERE c.contractCollection IS EMPTY
OR :contid NOT MEMBER OF c.contractCollection .
public List<Consultant> getAvailableConsultants( String cntrctId) {
return em.createQuery("SELECT c FROM Consultant c"
+ " WHERE c.contractCollection IS EMPTY OR :contid NOT MEMBER OF c.contractCollection ")
.setParameter("contid", cntrctId)
.getResultList();
The collection is a result of a many-to-many relationship which i thought holds the contractIDs
how can i get the query to check whether the parameter contid is not in the collection
Thnx

Answer 1

Hi Amasoni, I think you might want to review the JPA persistence basics: http://docs.oracle.com/javaee/6/tutorial/doc/bnbtl.html (or probably Java basics). As pointed out by qimbal2, c.contractCollection refers to a collection of Contract object, hence you won't be able to simply cast it to get its id.
Instead if you want to find out Consultants with no contracts with exceptions of some contract ids, you can use joins as such:
select distinct c
from Consultant c
left outer join c.contractCollection o
where o is null
or (o is not null and o <> 3)