diff options
5 files changed, 80 insertions, 26 deletions
diff --git a/activerecord/lib/active_record/associations/join_dependency/join_part.rb b/activerecord/lib/active_record/associations/join_dependency/join_part.rb index 3279e56e7d..2b1d888a9a 100644 --- a/activerecord/lib/active_record/associations/join_dependency/join_part.rb +++ b/activerecord/lib/active_record/associations/join_dependency/join_part.rb @@ -22,7 +22,7 @@ module ActiveRecord end def aliased_table - Arel::Nodes::TableAlias.new aliased_table_name, table + Arel::Nodes::TableAlias.new table, aliased_table_name end def ==(other) diff --git a/activerecord/lib/active_record/relation/calculations.rb b/activerecord/lib/active_record/relation/calculations.rb index c1842b1a96..869eebfa34 100644 --- a/activerecord/lib/active_record/relation/calculations.rb +++ b/activerecord/lib/active_record/relation/calculations.rb @@ -196,24 +196,22 @@ module ActiveRecord end def execute_simple_calculation(operation, column_name, distinct) #:nodoc: - column = aggregate_column(column_name) - # Postgresql doesn't like ORDER BY when there are no GROUP BY relation = except(:order) - select_value = operation_over_aggregate_column(column, operation, distinct) - relation.select_values = [select_value] + if operation == "count" && (relation.limit_value || relation.offset_value) + # Shortcut when limit is zero. + return 0 if relation.limit_value == 0 - query_builder = relation.arel + query_builder = build_count_subquery(relation, column_name, distinct) + else + column = aggregate_column(column_name) - if operation == "count" - limit = relation.limit_value - offset = relation.offset_value + select_value = operation_over_aggregate_column(column, operation, distinct) - unless limit && offset - query_builder.limit = nil - query_builder.offset = nil - end + relation.select_values = [select_value] + + query_builder = relation.arel end type_cast_calculated_value(@klass.connection.select_value(query_builder.to_sql), column_for(column_name), operation) @@ -312,5 +310,18 @@ module ActiveRecord select if select !~ /(,|\*)/ end end + + def build_count_subquery(relation, column_name, distinct) + column_alias = Arel.sql('count_column') + subquery_alias = Arel.sql('subquery_for_count') + + aliased_column = aggregate_column(column_name == :all ? 1 : column_name).as(column_alias) + relation.select_values = [aliased_column] + subquery = relation.arel.as(subquery_alias) + + sm = Arel::SelectManager.new relation.engine + select_value = operation_over_aggregate_column(column_alias, 'count', distinct) + sm.project(select_value).from(subquery) + end end end diff --git a/activerecord/test/cases/calculations_test.rb b/activerecord/test/cases/calculations_test.rb index c97f1ae634..654c4c9010 100644 --- a/activerecord/test/cases/calculations_test.rb +++ b/activerecord/test/cases/calculations_test.rb @@ -65,7 +65,7 @@ class CalculationsTest < ActiveRecord::TestCase c = Account.sum(:credit_limit, :group => :firm_id) [1,6,2].each { |firm_id| assert c.keys.include?(firm_id) } end - + def test_should_group_by_multiple_fields c = Account.count(:all, :group => ['firm_id', :credit_limit]) [ [nil, 50], [1, 50], [6, 50], [6, 55], [9, 53], [2, 60] ].each { |firm_and_limit| assert c.keys.include?(firm_and_limit) } @@ -109,27 +109,42 @@ class CalculationsTest < ActiveRecord::TestCase assert_equal [2, 6], c.keys.compact end - def test_limit_with_offset_is_kept + def test_limit_should_apply_before_count + accounts = Account.limit(3).where('firm_id IS NOT NULL') + + assert_equal 3, accounts.count(:firm_id) + assert_equal 3, accounts.select(:firm_id).count + end + + def test_count_should_shortcut_with_limit_zero + accounts = Account.limit(0) + + assert_no_queries { assert_equal 0, accounts.count } + end + + def test_limit_is_kept return if current_adapter?(:OracleAdapter) - queries = assert_sql { Account.limit(1).offset(1).count } + queries = assert_sql { Account.limit(1).count } assert_equal 1, queries.length assert_match(/LIMIT/, queries.first) - assert_match(/OFFSET/, queries.first) end - def test_offset_without_limit_removes_offset + def test_offset_is_kept + return if current_adapter?(:OracleAdapter) + queries = assert_sql { Account.offset(1).count } assert_equal 1, queries.length - assert_no_match(/LIMIT/, queries.first) - assert_no_match(/OFFSET/, queries.first) + assert_match(/OFFSET/, queries.first) end - def test_limit_without_offset_removes_limit - queries = assert_sql { Account.limit(1).count } + def test_limit_with_offset_is_kept + return if current_adapter?(:OracleAdapter) + + queries = assert_sql { Account.limit(1).offset(1).count } assert_equal 1, queries.length - assert_no_match(/LIMIT/, queries.first) - assert_no_match(/OFFSET/, queries.first) + assert_match(/LIMIT/, queries.first) + assert_match(/OFFSET/, queries.first) end def test_no_limit_no_offset diff --git a/activerecord/test/cases/finder_test.rb b/activerecord/test/cases/finder_test.rb index 014588b6d9..3c242667eb 100644 --- a/activerecord/test/cases/finder_test.rb +++ b/activerecord/test/cases/finder_test.rb @@ -209,9 +209,9 @@ class FinderTest < ActiveRecord::TestCase end def test_model_class_responds_to_first_bang - assert_equal topics(:first), Topic.order(:id).first! + assert Topic.first! + Topic.delete_all assert_raises ActiveRecord::RecordNotFound do - Topic.delete_all Topic.first! end end diff --git a/activerecord/test/cases/relations_test.rb b/activerecord/test/cases/relations_test.rb index 2304c20a5f..fc9df8c7a3 100644 --- a/activerecord/test/cases/relations_test.rb +++ b/activerecord/test/cases/relations_test.rb @@ -672,6 +672,34 @@ class RelationTest < ActiveRecord::TestCase assert_no_queries { assert_equal 9, best_posts.size } end + def test_size_with_limit + posts = Post.limit(10) + + assert_queries(1) { assert_equal 10, posts.size } + assert ! posts.loaded? + + best_posts = posts.where(:comments_count => 0) + best_posts.to_a # force load + assert_no_queries { assert_equal 9, best_posts.size } + end + + def test_size_with_zero_limit + posts = Post.limit(0) + + assert_no_queries { assert_equal 0, posts.size } + assert ! posts.loaded? + + posts.to_a # force load + assert_no_queries { assert_equal 0, posts.size } + end + + def test_empty_with_zero_limit + posts = Post.limit(0) + + assert_no_queries { assert_equal true, posts.empty? } + assert ! posts.loaded? + end + def test_count_complex_chained_relations posts = Post.select('comments_count').where('id is not null').group("author_id").where("comments_count > 0") |