diff options
4 files changed, 31 insertions, 0 deletions
diff --git a/activerecord/lib/active_record/associations.rb b/activerecord/lib/active_record/associations.rb index cb17b6e483..a1c8bd6e50 100755 --- a/activerecord/lib/active_record/associations.rb +++ b/activerecord/lib/active_record/associations.rb @@ -55,6 +55,12 @@ module ActiveRecord end end + class HasManyThroughCantCountOnColumnForGroupedAssociation < ActiveRecordError #:nodoc: + def initialize(owner, reflection, column_name) + super("Cannot count on column '#{column_name}' for association '#{owner.class.name}##{reflection.name}' grouped by '#{reflection.options[:group]}'.") + end + end + class EagerLoadPolymorphicError < ActiveRecordError #:nodoc: def initialize(reflection) super("Can not eagerly load the polymorphic association #{reflection.name.inspect}") diff --git a/activerecord/lib/active_record/associations/has_many_through_association.rb b/activerecord/lib/active_record/associations/has_many_through_association.rb index 1ca44d645c..96d0b73da2 100644 --- a/activerecord/lib/active_record/associations/has_many_through_association.rb +++ b/activerecord/lib/active_record/associations/has_many_through_association.rb @@ -124,6 +124,15 @@ module ActiveRecord column_name = "#{@reflection.quoted_table_name}.#{@reflection.klass.primary_key}" if column_name == :all options.merge!(:distinct => true) end + + if @reflection.options[:group] + unless column_name == :all + raise HasManyThroughCantCountOnColumnForGroupedAssociation.new(@owner, @reflection, column_name) + end + column_name = @reflection.options[:group] + options.merge!(:distinct => true) + end + @reflection.klass.send(:with_scope, construct_scope) { @reflection.klass.count(column_name, options) } end diff --git a/activerecord/test/cases/associations/join_model_test.rb b/activerecord/test/cases/associations/join_model_test.rb index f59fe70654..8da13d8b1b 100644 --- a/activerecord/test/cases/associations/join_model_test.rb +++ b/activerecord/test/cases/associations/join_model_test.rb @@ -603,6 +603,21 @@ class AssociationsJoinModelTest < ActiveRecord::TestCase end end + def test_group_has_many_through_should_use_group_for_count + using_length = authors(:david).reload.grouped_comments.length # all associated comments are read first + using_count = authors(:david).reload.grouped_comments.count # associated comments are only counted + assert_equal using_count, using_length + + commented_posts = authors(:david).comments.map(&:post).uniq.size # count commented posts manually + assert_equal commented_posts, authors(:david).grouped_comments.count + end + + def test_group_has_many_through_should_not_allow_column_name_for_count + assert_raises ActiveRecord::HasManyThroughCantCountOnColumnForGroupedAssociation do + authors(:david).grouped_comments.count(:id) + end + end + private # create dynamic Post models to allow different dependency options def find_post_with_dependency(post_id, association, association_name, dependency) diff --git a/activerecord/test/models/author.rb b/activerecord/test/models/author.rb index 593d77342e..64e4d38114 100644 --- a/activerecord/test/models/author.rb +++ b/activerecord/test/models/author.rb @@ -20,6 +20,7 @@ class Author < ActiveRecord::Base has_many :funky_comments, :through => :posts, :source => :comments has_many :ordered_uniq_comments, :through => :posts, :source => :comments, :uniq => true, :order => 'comments.id' has_many :ordered_uniq_comments_desc, :through => :posts, :source => :comments, :uniq => true, :order => 'comments.id DESC' + has_many :grouped_comments, :through => :posts, :source => :comments, :group => 'comments.post_id' has_many :special_posts has_many :special_post_comments, :through => :special_posts, :source => :comments |