diff options
5 files changed, 61 insertions, 12 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 9c0c4e3ef0..6e1f43cce6 100644 --- a/activerecord/lib/active_record/connection_adapters/abstract/schema_statements.rb +++ b/activerecord/lib/active_record/connection_adapters/abstract/schema_statements.rb @@ -706,12 +706,20 @@ module ActiveRecord end # SELECT DISTINCT clause for a given set of columns and a given ORDER BY clause. - # Both PostgreSQL and Oracle overrides this for custom DISTINCT syntax. # - # distinct("posts.id", "posts.created_at desc") + # distinct("posts.id", ["posts.created_at desc"]) # def distinct(columns, order_by) - "DISTINCT #{columns}" + "DISTINCT #{columns_for_distinct(columns, order_by)}" + 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 + # require the order columns appear in the SELECT. + # + # columns_for_distinct("posts.id", ["posts.created_at desc"]) + def columns_for_distinct(columns, orders) + columns end # Adds timestamps (+created_at+ and +updated_at+) columns to the named table. diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb b/activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb index 98916b06a5..8feee23df0 100644 --- a/activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb +++ b/activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb @@ -467,14 +467,9 @@ module ActiveRecord end end - # Returns a SELECT DISTINCT clause for a given set of columns and a given ORDER BY clause. - # # PostgreSQL requires the ORDER BY columns in the select list for distinct queries, and # requires that the ORDER BY include the distinct column. - # - # distinct("posts.id", ["posts.created_at desc"]) - # # => "DISTINCT posts.id, posts.created_at AS alias_0" - def distinct(columns, orders) #:nodoc: + def columns_for_distinct(columns, orders) #:nodoc: order_columns = orders.map{ |s| # Convert Arel node to string s = s.to_sql unless s.is_a?(String) @@ -482,7 +477,7 @@ module ActiveRecord s.gsub(/\s+(ASC|DESC)\s*(NULLS\s+(FIRST|LAST)\s*)?/i, '') }.reject(&:blank?).map.with_index { |column, i| "#{column} AS alias_#{i}" } - [super].concat(order_columns).join(', ') + [super, *order_columns].join(', ') end end end diff --git a/activerecord/lib/active_record/relation/finder_methods.rb b/activerecord/lib/active_record/relation/finder_methods.rb index 72e9272cd7..ff825e52c1 100644 --- a/activerecord/lib/active_record/relation/finder_methods.rb +++ b/activerecord/lib/active_record/relation/finder_methods.rb @@ -245,9 +245,9 @@ module ActiveRecord def construct_limited_ids_condition(relation) orders = relation.order_values.map { |val| val.presence }.compact - values = @klass.connection.distinct("#{quoted_table_name}.#{primary_key}", orders) + values = @klass.connection.columns_for_distinct("#{quoted_table_name}.#{quoted_primary_key}", orders) - relation = relation.dup.select(values) + relation = relation.dup.select(values).distinct! id_rows = @klass.connection.select_all(relation.arel, 'SQL', relation.bind_values) ids_array = id_rows.map {|row| row[primary_key]} diff --git a/activerecord/test/cases/adapters/postgresql/postgresql_adapter_test.rb b/activerecord/test/cases/adapters/postgresql/postgresql_adapter_test.rb index 17d77c5454..ff7eb86969 100644 --- a/activerecord/test/cases/adapters/postgresql/postgresql_adapter_test.rb +++ b/activerecord/test/cases/adapters/postgresql/postgresql_adapter_test.rb @@ -230,21 +230,41 @@ module ActiveRecord @connection.distinct("posts.id", []) end + def test_columns_for_distinct_zero_orders + assert_equal "posts.id", + @connection.columns_for_distinct("posts.id", []) + end + def test_distinct_one_order assert_equal "DISTINCT posts.id, posts.created_at AS alias_0", @connection.distinct("posts.id", ["posts.created_at desc"]) end + def test_columns_for_distinct_one_order + assert_equal "posts.id, posts.created_at AS alias_0", + @connection.columns_for_distinct("posts.id", ["posts.created_at desc"]) + end + def test_distinct_few_orders assert_equal "DISTINCT posts.id, posts.created_at AS alias_0, posts.position AS alias_1", @connection.distinct("posts.id", ["posts.created_at desc", "posts.position asc"]) end + def test_columns_for_distinct_few_orders + assert_equal "posts.id, posts.created_at AS alias_0, posts.position AS alias_1", + @connection.columns_for_distinct("posts.id", ["posts.created_at desc", "posts.position asc"]) + end + def test_distinct_blank_not_nil_orders assert_equal "DISTINCT posts.id, posts.created_at AS alias_0", @connection.distinct("posts.id", ["posts.created_at desc", "", " "]) end + def test_columns_for_distinct_blank_not_nil_orders + assert_equal "posts.id, posts.created_at AS alias_0", + @connection.columns_for_distinct("posts.id", ["posts.created_at desc", "", " "]) + end + def test_distinct_with_arel_order order = Object.new def order.to_sql @@ -254,11 +274,25 @@ module ActiveRecord @connection.distinct("posts.id", [order]) 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", + @connection.columns_for_distinct("posts.id", [order]) + end + def test_distinct_with_nulls assert_equal "DISTINCT posts.title, posts.updater_id AS alias_0", @connection.distinct("posts.title", ["posts.updater_id desc nulls first"]) assert_equal "DISTINCT posts.title, posts.updater_id AS alias_0", @connection.distinct("posts.title", ["posts.updater_id desc nulls last"]) end + def test_columns_for_distinct_with_nulls + assert_equal "posts.title, posts.updater_id AS alias_0", @connection.columns_for_distinct("posts.title", ["posts.updater_id desc nulls first"]) + assert_equal "posts.title, posts.updater_id AS alias_0", @connection.columns_for_distinct("posts.title", ["posts.updater_id desc nulls last"]) + end + def test_raise_error_when_cannot_translate_exception assert_raise TypeError do @connection.send(:log, nil) { @connection.execute(nil) } diff --git a/activerecord/test/cases/finder_test.rb b/activerecord/test/cases/finder_test.rb index 7db9aef218..6f0de42aef 100644 --- a/activerecord/test/cases/finder_test.rb +++ b/activerecord/test/cases/finder_test.rb @@ -98,6 +98,18 @@ class FinderTest < ActiveRecord::TestCase assert !Topic.includes(:replies).limit(1).where('0 = 1').exists? end + def test_exists_with_distinct_association_includes_and_limit + author = Author.first + assert !author.unique_categorized_posts.includes(:special_comments).limit(0).exists? + assert author.unique_categorized_posts.includes(:special_comments).limit(1).exists? + end + + def test_exists_with_distinct_association_includes_limit_and_order + author = Author.first + assert !author.unique_categorized_posts.includes(:special_comments).order('comments.taggings_count DESC').limit(0).exists? + assert author.unique_categorized_posts.includes(:special_comments).order('comments.taggings_count DESC').limit(1).exists? + end + def test_exists_with_empty_table_and_no_args_given Topic.delete_all assert !Topic.exists? |