Question

I had the following function. It worked, but I don’t like the way it looked.

# in user.rb
def awarded_requests
  Request.joins('JOIN application ON application.request_id = request.id').where('accepted = true AND application.user_id = ?', self.id)
end

Then I refactored it to something that’s clearly an improvement, but probably not simplest possible form:

def awarded_requests
  Request.find(self.applications.accepted.map(&:request_id))
end

Can this be simplified further?

Answer 1

If you set up has many relationship, you can filter out those requests by merging a scope.

class User
  has_many :applications

  def awarded_requests
    Request.joins(:applications).merge(applications.accepted)
  end
end

Note that applications.accepted is not an array of records but a scope. This is how Active Record represents a part of SQL query internally, therefore it can smartly combine a few of them.