Scopes and associations not working

Question

I'm trying to return records where the association is either present or not:

I tried these scopes:

class Booking < ActiveRecord::Base
  has_one :availability

  scope :with_availability, -> {where{availability.not_eq nil}}
  scope :without_availability, -> {where{availability.eq nil}}
end

Which one doesn't work? Second one looks good (note the round braces `()` in first one) — Alexey Shein, Sep 24 '15 at 20:48
Do you get any error? Could you please show `Booking.without_availability.to_sql`? — Alexey Shein, Sep 24 '15 at 20:57
`"SELECT \"bookings\".* FROM \"bookings\" WHERE \"bookings\".\"availability\" IS NULL"` — Batman, Sep 24 '15 at 21:05
what fields are you doing the comparison with? availability is a table. Am I missing something? — patrickh003, Sep 24 '15 at 21:05
Yea availability is a table. ` Booking should have 1 Availability. But sometimes a booking gets created with an Associated availability (bug I haven't tracked down yet). So I'm trying to return all Bookings which might not have an Availability associated with it. — Batman, Sep 24 '15 at 21:21

score 3 · Accepted Answer · answered Sep 24 '15 at 21:21

3

Try this:

class Booking < ActiveRecord::Base
  has_one :availability

  scope :with_availability, -> { joins{availability} }
  scope :without_availability, -> { joins{availability.outer}.where{availability.id.eq nil} }
end

answered Sep 24 '15 at 21:21

Alexey Shein

7,342
1
25
38

score 0 · Answer 2 · answered Sep 24 '15 at 20:49

0

Use instance methods instead

def with_availability
  availability.present?
end

def without_availability
  availability.blank?
end

answered Sep 24 '15 at 20:49

patrickh003

168
1
5

This wont work, I'm trying to get all records which match those conditions. – Batman Sep 24 '15 at 20:51

score 0 · Answer 3 · edited May 23 '17 at 10:27

I know there is better way but this should work as well:

class Booking < ActiveRecord::Base
  has_one :availability

  scope :with_availability, -> {where(id: Availability.pluck(:booking_id))}
  scope :without_availability, -> {where.not(id: Availability.pluck(:booking_id))}
end

Also I tried to reproduce the solution by the link below but I didn't manage to do this (but it could be helpful):

Rails - has_one relationship : scopes for associated and non-associated objects

Scopes and associations not working

3 Answers3