QueryDSL code generation for ManyToMany
Question
I'm porting some complex JPQL queries in a large Hibernate/JPA2 application to use QueryDSL 2.3.0, and I'm stuck on one.
My Client
entity contains
@ManyToMany
private List<Group> groups;
My existing query fragment is
EXISTS(SELECT g FROM Group g WHERE g MEMBER OF slr.groups AND
UPPER(g.description) LIKE :group)
The QueryDSL code generation has produced the following in my QClient
class:
public final SimplePath<java.util.List<Group>> groups =
createSimple("groups", java.util.List.class);
The code generation using SimplePath
doesn't let me use the in
or contains
methods to query membership. I think I need a CollectionPath
instead. Is there a way to annotate the Client
class so that QueryDSL uses the correct type for querying a collection?
Solution
I have an answer. This looks like a bug introduced in QueryDSL 2.2.5, which only happens when working in Eclipse.
The correct solution is to not use Eclipse to generate the source (don't enable annotation processing). Instead, I'm using m2eclipse
and generating the source in Maven.
For reference, my first workaround was to extend the generated QClient
class with my own QQClient
class, which adds one member:
public final ListPath<Group, QGroup> fixedgroups =
createList("groups", Group.class, QGroup.class);
At that point the equivalent to my original query is:
QGroup g = QGroup.group;
JPQLSubQuery subquery = new JPQLSubQuery().from(g);
subquery = subquery.where(slr.fixedgroups.contains(g),
g.description.upper().like("%" + group.toUpperCase() + "%"));
query = query.where(subquery.exists());
(query
is the larger query this is part of. slr
is an instance of QQClient
brought into the outer query by a left join.)