Question

Domain outlay:

class User {
    String username
    static hasMany = [userRoles: UserRole]
}
class Role {
    String authority
}
class UserRole {
    User user
    Role role
    static belongsTo = [User, Role]
}

That is a condensed version of what you’ll normally find when you install the grails spring-security-core plugin.

Now, a user can have more than one role. Thus, an admin can be a normal user. User:UserRole = 1:M

In SQL it would be easy to get a set of users where there isn’t a user role attached to it.
How does one do it with the Grails criteria builder?

As a stop gap fix (until I get a nice answer that is not basically plugging SQL into Grails), I basically get all the admin users as a set, then I get the list of users as another, and one for one remove all the admin user out. Ugly, but it works (slowly):

def existing = UserRole.createCriteria().listDistinct {
    eq("role",adminRole)
}.collect{it.user} as Set

def f = User.createCriteria().listDistinct {
    userRoles {
        ne("role",adminRole)
    }
}.collect{it} as Set

existing.each { ex ->
        f.each { non ->
            if (non.id == ex.id) {
                f.remove(non)
            }
        }
}

In the code above, if you do f.removeAll(existing) it doesn’t work.

I think this would be a nice question to answer as you can apply the same to other scenarios as well.

Thanks in advance!

Answer 1

I’m not sure how to do it with a criteria query, but this HQL works:

def role = ...
def usersWithoutRole = UserRole.executeQuery(
   'from User u where u not in ' +
       '(select ur.user from UserRole ur where ur.role=:r)',
   [r: role])