Casting required for queries with multiple entity paths

[Dmytro Maidaniuk]

Hi,

I can't find in documentation any full example with usage of QueryDSL for multiple paths. For example, for next code

new JPAQuery<Void>(getEntityManager()).from(qEntityOne, qEntityTwo)
    .where(qEntityOne.fieldA.eq(qEntityTwo.fieldB))
    .leftJoin(qEntityOne.fieldC).fetchJoin()

Java compiler said that class QueryBase don't have .leftJoin() method. I need first cast query back to JPAQuery and only after that call left join.

What I'm doing wrong?

Thanks,
Dmytro

[Ruben Dijkstra]

Could you check that you are not using rawtypes?

I copied your query and inserted entity types that I had, and it compiled.

However, using raw types, the compiler only inserts the upper bound, which is QueryBase.

This results in the compiler error you encountered.

Br,

Ruben

[Dmytro Maidaniuk]

Hi Ruben,

Nop, I don't use rawtypes here. I also used my own entity types for this query.
Casting needed after calling method where(...) which return not a JPAQuery, but QueryBase.

Could you post here your full query sample, please?

Thanks,
Dmytro

[Dmytro Maidaniuk]

Hi Ruben,


I found reason for casting problem. I missed Void type in return statement of helper method.

Now I can't apply Projections.map(key, value) as described in example :

Map<String, String> map = query()
                               .select(Projections.map(employee.firstname, employee.lastname))
                               .from(employee)
                               .fetch();

Method fetch() return a list, not a map. In QueryDSL 3.6.x was a method query.map(...) for this purpose. What I need to do in QueryDSL 4.x now?

Regards,
Dmytro

[Ruben Dijkstra]

It seems I probably misinterpreted the question back then.

I adjusted the comment, since most people would want the GroupBy API for making Map results.

query()

.from(employee)

.transform(GroupBy.groupBy(employee.firstName).as(employee.lastName))

Then the map is keyed by the value of the expression, and not the expression itself.

I hope this clears up the confusion.

Br,

Ruben

[Dmytro Maidaniuk]

Hi Ruben,

Yes, correct. Now it works.
Also I found more old your answer for similar question here: https://groups.google.com/forum/#!topic/querydsl/1rMMrewx9Ts
Thanks for help with QueryDSL 4 API!

Regards,
Dmytro