CODEWITHSUNDEEP
ruby-on-railspostgresqlruby-on-rails-4activerecordassociations
Chris Edwards
Chris Edwards

Reputation: 3602

Rails association using OR

Given a List model with the following associations:

has_many :list_group_memberships, dependent: :destroy
has_many :groups, through: :list_group_memberships
has_many :users, -> { unscope(:order).uniq }, through: :groups, source: :users

Basically I need to return the following but as an ActiveRecord::Relation, not an array:

def users
  super + [user]
end

Ideally, the users relation would use an or scope, but I can't work it out.

Upvotes: 0

Views: 34

Answers (2)

Chris Edwards
Chris Edwards

Reputation: 3602

I managed to solve it using the active_record_union gem and the following:

def users
  super.union(User.where(id: user_id))
end

EDIT: I changed my implementation to use the solution posted by @mysmallidea

Upvotes: 0

Ryenski
Ryenski

Reputation: 9692

You could do this without the union gem:

# app/models/list.rb
def users_with_current_user
  # Assuming `users` is the has_many :users relation on the list
  # and `user` is a belongs_to relation on this list...
  User.where(id: users).or(User.where(id: user))
end

This will automatically create an INNER JOIN on the list_group_memberships table.

Upvotes: 1

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