diff --git a/activerecord/lib/active_record/relation.rb b/activerecord/lib/active_record/relation.rb index f0891440a6..0c32ad5139 100644 --- a/activerecord/lib/active_record/relation.rb +++ b/activerecord/lib/active_record/relation.rb @@ -1,3 +1,4 @@ +# -*- coding: utf-8 -*- require 'active_support/core_ext/object/blank' require 'active_support/core_ext/module/delegation' @@ -155,8 +156,8 @@ module ActiveRecord end queries.map do |sql| - @klass.connection.explain(sql) - end.join + "EXPLAIN for: #{sql}\n#{@klass.connection.explain(sql)}" + end.join("\n") end def to_a diff --git a/activerecord/test/cases/adapters/mysql2/explain_test.rb b/activerecord/test/cases/adapters/mysql2/explain_test.rb index 8ea777b72b..68ed361aeb 100644 --- a/activerecord/test/cases/adapters/mysql2/explain_test.rb +++ b/activerecord/test/cases/adapters/mysql2/explain_test.rb @@ -9,12 +9,15 @@ module ActiveRecord def test_explain_for_one_query explain = Developer.where(:id => 1).explain + assert_match %(EXPLAIN for: SELECT `developers`.* FROM `developers` WHERE `developers`.`id` = 1), explain assert_match %(developers | const), explain end def test_explain_with_eager_loading explain = Developer.where(:id => 1).includes(:audit_logs).explain + assert_match %(EXPLAIN for: SELECT `developers`.* FROM `developers` WHERE `developers`.`id` = 1), explain assert_match %(developers | const), explain + assert_match %(EXPLAIN for: SELECT `audit_logs`.* FROM `audit_logs` WHERE `audit_logs`.`developer_id` IN (1)), explain assert_match %(audit_logs | ALL), explain end end diff --git a/activerecord/test/cases/adapters/postgresql/explain_test.rb b/activerecord/test/cases/adapters/postgresql/explain_test.rb index 0d599ed37f..0b61f61572 100644 --- a/activerecord/test/cases/adapters/postgresql/explain_test.rb +++ b/activerecord/test/cases/adapters/postgresql/explain_test.rb @@ -9,6 +9,7 @@ module ActiveRecord def test_explain_for_one_query explain = Developer.where(:id => 1).explain + assert_match %(EXPLAIN for: SELECT "developers".* FROM "developers" WHERE "developers"."id" = 1), explain assert_match %(QUERY PLAN), explain assert_match %(Index Scan using developers_pkey on developers), explain end @@ -16,7 +17,9 @@ module ActiveRecord def test_explain_with_eager_loading explain = Developer.where(:id => 1).includes(:audit_logs).explain assert_match %(QUERY PLAN), explain + assert_match %(EXPLAIN for: SELECT "developers".* FROM "developers" WHERE "developers"."id" = 1), explain assert_match %(Index Scan using developers_pkey on developers), explain + assert_match %(EXPLAIN for: SELECT "audit_logs".* FROM "audit_logs" WHERE "audit_logs"."developer_id" IN (1)), explain assert_match %(Seq Scan on audit_logs), explain end end diff --git a/activerecord/test/cases/adapters/sqlite3/explain_test.rb b/activerecord/test/cases/adapters/sqlite3/explain_test.rb index e18892821d..b227bce680 100644 --- a/activerecord/test/cases/adapters/sqlite3/explain_test.rb +++ b/activerecord/test/cases/adapters/sqlite3/explain_test.rb @@ -9,12 +9,15 @@ module ActiveRecord def test_explain_for_one_query explain = Developer.where(:id => 1).explain + assert_match %(EXPLAIN for: SELECT "developers".* FROM "developers" WHERE "developers"."id" = 1), explain assert_match(/(SEARCH )?TABLE developers USING (INTEGER )?PRIMARY KEY/, explain) end def test_explain_with_eager_loading explain = Developer.where(:id => 1).includes(:audit_logs).explain + assert_match %(EXPLAIN for: SELECT "developers".* FROM "developers" WHERE "developers"."id" = 1), explain assert_match(/(SEARCH )?TABLE developers USING (INTEGER )?PRIMARY KEY/, explain) + assert_match %(EXPLAIN for: SELECT "audit_logs".* FROM "audit_logs" WHERE "audit_logs"."developer_id" IN (1)), explain assert_match(/(SCAN )?TABLE audit_logs/, explain) end end diff --git a/railties/guides/source/active_record_querying.textile b/railties/guides/source/active_record_querying.textile index ad12dca7e8..0f1f6eba4c 100644 --- a/railties/guides/source/active_record_querying.textile +++ b/railties/guides/source/active_record_querying.textile @@ -1287,6 +1287,7 @@ User.where(:id => 1).joins(:posts).explain may yield +EXPLAIN for: SELECT `users`.* FROM `users` INNER JOIN `posts` ON `posts`.`user_id` = `users`.`id` WHERE `users`.`id` = 1 ------------------------------------------------------------------------------------------ | id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra | ------------------------------------------------------------------------------------------ @@ -1302,6 +1303,7 @@ Active Record performs a pretty printing that emulates the one of the database shells. So, the same query running with the PostgreSQL adapter would yield instead +EXPLAIN for: SELECT "users".* FROM "users" INNER JOIN "posts" ON "posts"."user_id" = "users"."id" WHERE "users"."id" = 1 QUERY PLAN ------------------------------------------------------------------------------ Nested Loop Left Join (cost=0.00..37.24 rows=8 width=0) @@ -1324,12 +1326,15 @@ User.where(:id => 1).includes(:posts).explain yields +EXPLAIN for: SELECT `users`.* FROM `users` WHERE `users`.`id` = 1 ------------------------------------------------------------------------------------ | id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra | ------------------------------------------------------------------------------------ | 1 | SIMPLE | users | const | PRIMARY | PRIMARY | 4 | const | 1 | | ------------------------------------------------------------------------------------ 1 row in set (0.00 sec) + +EXPLAIN for: SELECT `posts`.* FROM `posts` WHERE `posts`.`user_id` IN (1) ------------------------------------------------------------------------------------- | id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra | -------------------------------------------------------------------------------------