Question

I think this is a simple problem, but i just cant get my head round the solution. If i have a collection of records (reports in this case):

@reports = Report.all,  :conditions => ["score > 10"]

and then i try to find the associated collection of other type of records (users in this case) i, naively, try this – but know from the offset that it wont work:

@users = User.find   :all,  :conditions => ["id IN (?)", @results.user_id]

So, how do i efficiently extract the @users collection of records?

Answer 1

Assuming that User has_many :reports

@users = User.joins(:reports) # all users that have reports

If you only want all users for some specific reports

@users = User.joins(:reports).where("reports.id IN (?)", @reports.map(&:id))