diff options
6 files changed, 81 insertions, 8 deletions
diff --git a/activerecord/lib/active_record/connection_adapters/abstract/schema_statements.rb b/activerecord/lib/active_record/connection_adapters/abstract/schema_statements.rb index 7bf548fcba..a918a8b035 100644 --- a/activerecord/lib/active_record/connection_adapters/abstract/schema_statements.rb +++ b/activerecord/lib/active_record/connection_adapters/abstract/schema_statements.rb @@ -1028,11 +1028,12 @@ module ActiveRecord end # Given a set of columns and an ORDER BY clause, returns the columns for a SELECT DISTINCT. - # Both PostgreSQL and Oracle overrides this for custom DISTINCT syntax - they + # PostgreSQL, MySQL, and Oracle overrides this for custom DISTINCT syntax - they # require the order columns appear in the SELECT. # # columns_for_distinct("posts.id", ["posts.created_at desc"]) - def columns_for_distinct(columns, orders) #:nodoc: + # + def columns_for_distinct(columns, orders) # :nodoc: columns end diff --git a/activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb b/activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb index 863d8d3b8f..0615e646b1 100644 --- a/activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb +++ b/activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb @@ -773,6 +773,21 @@ module ActiveRecord end end + # In MySQL 5.7.5 and up, ONLY_FULL_GROUP_BY affects handling of queries that use + # DISTINCT and ORDER BY. It requires the ORDER BY columns in the select list for + # distinct queries, and requires that the ORDER BY include the distinct column. + # See https://dev.mysql.com/doc/refman/5.7/en/group-by-handling.html + def columns_for_distinct(columns, orders) # :nodoc: + order_columns = orders.reject(&:blank?).map { |s| + # Convert Arel node to string + s = s.to_sql unless s.is_a?(String) + # Remove any ASC/DESC modifiers + s.gsub(/\s+(?:ASC|DESC)\b/i, '') + }.reject(&:blank?).map.with_index { |column, i| "#{column} AS alias_#{i}" } + + [super, *order_columns].join(', ') + end + def strict_mode? self.class.type_cast_config_to_boolean(@config.fetch(:strict, true)) end @@ -952,11 +967,13 @@ module ActiveRecord subsubselect = select.clone subsubselect.projections = [key] + # Materialize subquery by adding distinct + # to work with MySQL 5.7.6 which sets optimizer_switch='derived_merge=on' + subsubselect.distinct unless select.limit || select.offset || select.orders.any? + subselect = Arel::SelectManager.new(select.engine) subselect.project Arel.sql(key.name) - # Materialized subquery by adding distinct - # to work with MySQL 5.7.6 which sets optimizer_switch='derived_merge=on' - subselect.from subsubselect.distinct.as('__active_record_temp') + subselect.from subsubselect.as('__active_record_temp') end def mariadb? diff --git a/activerecord/test/cases/adapters/mysql2/mysql2_adapter_test.rb b/activerecord/test/cases/adapters/mysql2/mysql2_adapter_test.rb new file mode 100644 index 0000000000..4efd728754 --- /dev/null +++ b/activerecord/test/cases/adapters/mysql2/mysql2_adapter_test.rb @@ -0,0 +1,44 @@ +require "cases/helper" + +class Mysql2AdapterTest < ActiveRecord::Mysql2TestCase + def setup + @conn = ActiveRecord::Base.connection + end + + def test_columns_for_distinct_zero_orders + assert_equal "posts.id", + @conn.columns_for_distinct("posts.id", []) + end + + def test_columns_for_distinct_one_order + assert_equal "posts.id, posts.created_at AS alias_0", + @conn.columns_for_distinct("posts.id", ["posts.created_at desc"]) + end + + def test_columns_for_distinct_few_orders + assert_equal "posts.id, posts.created_at AS alias_0, posts.position AS alias_1", + @conn.columns_for_distinct("posts.id", ["posts.created_at desc", "posts.position asc"]) + end + + def test_columns_for_distinct_with_case + assert_equal( + 'posts.id, CASE WHEN author.is_active THEN UPPER(author.name) ELSE UPPER(author.email) END AS alias_0', + @conn.columns_for_distinct('posts.id', + ["CASE WHEN author.is_active THEN UPPER(author.name) ELSE UPPER(author.email) END"]) + ) + end + + def test_columns_for_distinct_blank_not_nil_orders + assert_equal "posts.id, posts.created_at AS alias_0", + @conn.columns_for_distinct("posts.id", ["posts.created_at desc", "", " "]) + end + + def test_columns_for_distinct_with_arel_order + order = Object.new + def order.to_sql + "posts.created_at desc" + end + assert_equal "posts.id, posts.created_at AS alias_0", + @conn.columns_for_distinct("posts.id", [order]) + end +end diff --git a/activerecord/test/cases/finder_test.rb b/activerecord/test/cases/finder_test.rb index 9f90ab79a1..75a74c052d 100644 --- a/activerecord/test/cases/finder_test.rb +++ b/activerecord/test/cases/finder_test.rb @@ -19,7 +19,7 @@ require 'models/car' require 'models/tyre' class FinderTest < ActiveRecord::TestCase - fixtures :companies, :topics, :entrants, :developers, :developers_projects, :posts, :comments, :accounts, :authors, :customers, :categories, :categorizations, :cars + fixtures :companies, :topics, :entrants, :developers, :developers_projects, :posts, :comments, :accounts, :authors, :author_addresses, :customers, :categories, :categorizations, :cars def test_find_by_id_with_hash assert_raises(ActiveRecord::StatementInvalid) do @@ -993,10 +993,13 @@ class FinderTest < ActiveRecord::TestCase end def test_find_with_order_on_included_associations_with_construct_finder_sql_for_association_limiting_and_is_distinct - assert_equal 2, Post.includes(authors: :author_address).order('author_addresses.id DESC ').limit(2).to_a.size + assert_equal 2, Post.includes(authors: :author_address). + where.not(author_addresses: { id: nil }). + order('author_addresses.id DESC').limit(2).to_a.size assert_equal 3, Post.includes(author: :author_address, authors: :author_address). - order('author_addresses_authors.id DESC ').limit(3).to_a.size + where.not(author_addresses_authors: { id: nil }). + order('author_addresses_authors.id DESC').limit(3).to_a.size end def test_find_with_nil_inside_set_passed_for_one_attribute diff --git a/activerecord/test/fixtures/author_addresses.yml b/activerecord/test/fixtures/author_addresses.yml index 7b90572187..cf75e5998d 100644 --- a/activerecord/test/fixtures/author_addresses.yml +++ b/activerecord/test/fixtures/author_addresses.yml @@ -3,3 +3,9 @@ david_address: david_address_extra: id: 2 + +mary_address: + id: 3 + +bob_address: + id: 4 diff --git a/activerecord/test/fixtures/authors.yml b/activerecord/test/fixtures/authors.yml index 832236a486..41c124179e 100644 --- a/activerecord/test/fixtures/authors.yml +++ b/activerecord/test/fixtures/authors.yml @@ -9,7 +9,9 @@ david: mary: id: 2 name: Mary + author_address_id: 3 bob: id: 3 name: Bob + author_address_id: 4 |