How do I search for elements whose collection contains another element in Grails?

Question

Let\'s say I have a domain class called \"User\" which can follow other \"User\" objects. It does so having a field specified as:

def hasMany=[followedUsers:User         


        

Answer 1

You can use this HQL query:

User.executeQuery(
   'select u from User u where :follower in elements(u.followedUsers)',
   [follower: userInstance])

Answer 2

In my opinion, this syntax is much cleaner:

User.withCriteria { followedUsers{ eq('id', userInstance.id) } }