diff options
4 files changed, 26 insertions, 1 deletions
diff --git a/activerecord/CHANGELOG.md b/activerecord/CHANGELOG.md index 9b2e9c4660..a108a1b2a9 100644 --- a/activerecord/CHANGELOG.md +++ b/activerecord/CHANGELOG.md @@ -1,3 +1,14 @@ +* `has_one` and `belongs_to` accessors don't add ORDER BY to the queries anymore. + + Since Rails 4.0, we add an ORDER BY in the `first` method to ensure consistent results + among different database engines. But for singular associations this behavior is not needed + since we will have one record to return. As this ORDER BY option can lead some performance + issues we are removing it for singular associations accessors. + + Fixes #12623. + + *Rafael Mendonça França* + * Prepend table name for column names passed to `Relation#select`. Example: diff --git a/activerecord/lib/active_record/associations/singular_association.rb b/activerecord/lib/active_record/associations/singular_association.rb index e4500af5b2..399aff378a 100644 --- a/activerecord/lib/active_record/associations/singular_association.rb +++ b/activerecord/lib/active_record/associations/singular_association.rb @@ -39,7 +39,7 @@ module ActiveRecord end def find_target - if record = scope.first + if record = scope.take set_inverse_instance record end end diff --git a/activerecord/test/cases/associations/belongs_to_associations_test.rb b/activerecord/test/cases/associations/belongs_to_associations_test.rb index 3205d0c28b..2283ba66db 100644 --- a/activerecord/test/cases/associations/belongs_to_associations_test.rb +++ b/activerecord/test/cases/associations/belongs_to_associations_test.rb @@ -28,6 +28,13 @@ class BelongsToAssociationsTest < ActiveRecord::TestCase assert_equal companies(:first_firm).name, firm.name end + def test_belongs_to_does_not_use_order_by + ActiveRecord::SQLCounter.clear_log + Client.find(3).firm + ensure + assert ActiveRecord::SQLCounter.log_all.all? { |sql| /order by/i !~ sql }, 'ORDER BY was used in the query' + end + def test_belongs_to_with_primary_key client = Client.create(:name => "Primary key client", :firm_name => companies(:first_firm).name) assert_equal companies(:first_firm).name, client.firm_with_primary_key.name diff --git a/activerecord/test/cases/associations/has_one_associations_test.rb b/activerecord/test/cases/associations/has_one_associations_test.rb index 5a41461edf..d4edef03d6 100644 --- a/activerecord/test/cases/associations/has_one_associations_test.rb +++ b/activerecord/test/cases/associations/has_one_associations_test.rb @@ -22,6 +22,13 @@ class HasOneAssociationsTest < ActiveRecord::TestCase assert_equal Account.find(1).credit_limit, companies(:first_firm).account.credit_limit end + def test_has_one_does_not_use_order_by + ActiveRecord::SQLCounter.clear_log + companies(:first_firm).account + ensure + assert ActiveRecord::SQLCounter.log_all.all? { |sql| /order by/i !~ sql }, 'ORDER BY was used in the query' + end + def test_has_one_cache_nils firm = companies(:another_firm) assert_queries(1) { assert_nil firm.account } |