diff options
3 files changed, 24 insertions, 2 deletions
diff --git a/activerecord/CHANGELOG.md b/activerecord/CHANGELOG.md index f13a80195a..f7fdb6755d 100644 --- a/activerecord/CHANGELOG.md +++ b/activerecord/CHANGELOG.md @@ -1,3 +1,10 @@ +* Improved partial writes with HABTM and has many through associations + to fire database query only if relation has been changed. + + Fixes #19663. + + *Mehmet Emin İNAÇ* + * Rework `ActiveRecord::Relation#last` 1. Never perform additional SQL on loaded relation @@ -18,7 +25,6 @@ *Bogdan Gusiev* - * Allow `joins` to be unscoped. Closes #13775. diff --git a/activerecord/lib/active_record/associations/has_many_through_association.rb b/activerecord/lib/active_record/associations/has_many_through_association.rb index 36fc381343..7ddb96db13 100644 --- a/activerecord/lib/active_record/associations/has_many_through_association.rb +++ b/activerecord/lib/active_record/associations/has_many_through_association.rb @@ -86,7 +86,10 @@ module ActiveRecord end def save_through_record(record) - build_through_record(record).save! + association = build_through_record(record) + if association.changed? + association.save! + end ensure @through_records.delete(record.object_id) end diff --git a/activerecord/test/cases/associations/has_and_belongs_to_many_associations_test.rb b/activerecord/test/cases/associations/has_and_belongs_to_many_associations_test.rb index 5c4586da19..cab9dff6ca 100644 --- a/activerecord/test/cases/associations/has_and_belongs_to_many_associations_test.rb +++ b/activerecord/test/cases/associations/has_and_belongs_to_many_associations_test.rb @@ -982,4 +982,17 @@ class HasAndBelongsToManyAssociationsTest < ActiveRecord::TestCase Project.first.developers_required_by_default.create!(name: "Sean", salary: 50000) end end + + def test_has_and_belongs_to_many_while_partial_writes_false + begin + original_partial_writes = ActiveRecord::Base.partial_writes + ActiveRecord::Base.partial_writes = false + developer = Developer.new(name: "Mehmet Emin İNAÇ") + developer.projects << Project.new(name: "Bounty") + + assert developer.save + ensure + ActiveRecord::Base.partial_writes = original_partial_writes + end + end end |