Question

I have two tables: User and Roles. and User is mapped to roles using a many to many relationship.
what i want, is to get a selection of columns including the ones in role. So I created the following named query:

SELECT u.username, u.password, u.salt, u.enabled, u.roles FROM User u WHERE u.username = :username

However Hibernate is failing to compile, and the SQL log is the following:

Hibernate: 
select
    user0_.username as col_0_0_,
    user0_.password as col_1_0_,
    user0_.salt as col_2_0_,
    user0_.enabled as col_3_0_,
    . as col_4_0_,
    role2_.id as id42_,
    role2_.friendly_name as friendly2_42_,
    role2_.name as name42_ 
from
    users user0_ 
inner join
    users_roles roles1_ 
        on user0_.id=roles1_.users_id 
inner join
    roles role2_ 
        on roles1_.roles_id=role2_.id 
where
    user0_.username=?

what intrigues me is . as col_4_0_, ! It is causing the problem, but why would hibernate include it, and how to fix this issue?

Many Thanks

Answer 1

Either query for User instances, and fecth the roles with them:

select distinct u from User u
left join fetch u.roles
where u.username = :username

Or use a query that returns scalars, but then you can’t just treat the collection af roles as if it were a scalar:

select u.username, u.password, u.salt, u.enabled, r.id, r.name
from User u 
left join u.roles r
where u.username = :username

Side note: it should be userName, not username, to respect the standard Java naming conventions.