instance method `associated`

Ruby on Rails 8.0.4

Since v7.0.10

Available in: v7.0.10 v7.1.6 v7.2.3 v8.0.4 v8.1.2

Compare with:

associated(*associations)

Returns a new relation with joins and where clause to identify associated relations.

For example, posts that are associated to a related author:

Post.where.associated(:author)
# SELECT "posts".* FROM "posts"
# INNER JOIN "authors" ON "authors"."id" = "posts"."author_id"
# WHERE "authors"."id" IS NOT NULL

Additionally, multiple relations can be combined. This will return posts associated to both an author and any comments:

Post.where.associated(:author, :comments)
# SELECT "posts".* FROM "posts"
# INNER JOIN "authors" ON "authors"."id" = "posts"."author_id"
# INNER JOIN "comments" ON "comments"."post_id" = "posts"."id"
# WHERE "authors"."id" IS NOT NULL AND "comments"."id" IS NOT NULL

You can define join type in the scope and associated will not use JOIN by default.

 Post.left_joins(:author).where.associated(:author)
 # SELECT "posts".* FROM "posts"
 # LEFT OUTER JOIN "authors" "authors"."id" = "posts"."author_id"
 # WHERE "authors"."id" IS NOT NULL

 Post.left_joins(:comments).where.associated(:author)
 # SELECT "posts".* FROM "posts"
 # INNER JOIN "authors" ON "authors"."id" = "posts"."author_id"
 # LEFT OUTER JOIN "comments" ON "comments"."post_id" = "posts"."id"
#  WHERE "author"."id" IS NOT NULL

Parameters

associations rest

Source

# File activerecord/lib/active_record/relation/query_methods.rb, line 88
      def associated(*associations)
        associations.each do |association|
          reflection = scope_association_reflection(association)
          unless @scope.joins_values.include?(reflection.name) || @scope.left_outer_joins_values.include?(reflection.name)
            @scope.joins!(association)
          end

          association_conditions = Array(reflection.association_primary_key).index_with(nil)
          if reflection.options[:class_name]
            self.not(association => association_conditions)
          else
            self.not(reflection.table_name => association_conditions)
          end
        end

        @scope
      end

Defined in activerecord/lib/active_record/relation/query_methods.rb line 88 · View on GitHub · Improve this page · Find usages on GitHub

Defined in ActiveRecord::QueryMethods::WhereChain

Signature

Parameters