diff options
| -rw-r--r-- | activerecord/lib/active_record/relation/calculations.rb | 10 | ||||
| -rw-r--r-- | activerecord/test/cases/calculations_test.rb | 4 |
2 files changed, 14 insertions, 0 deletions
diff --git a/activerecord/lib/active_record/relation/calculations.rb b/activerecord/lib/active_record/relation/calculations.rb index db894c8aa9..f388b75c05 100644 --- a/activerecord/lib/active_record/relation/calculations.rb +++ b/activerecord/lib/active_record/relation/calculations.rb @@ -139,6 +139,16 @@ module ActiveRecord end end + # Pluck all the ID's for the relation using the table's primary key + # + # Examples: + # + # Person.ids # SELECT people.id FROM people + # Person.joins(:companies).ids # SELECT people.id FROM PEOPLE INNER JOIN companies ON companies.person_id = people.id + def ids + pluck primary_key + end + private def perform_calculation(operation, column_name, options = {}) diff --git a/activerecord/test/cases/calculations_test.rb b/activerecord/test/cases/calculations_test.rb index 2e566ff873..4ddd99ea97 100644 --- a/activerecord/test/cases/calculations_test.rb +++ b/activerecord/test/cases/calculations_test.rb @@ -465,4 +465,8 @@ class CalculationsTest < ActiveRecord::TestCase Company.create!(:name => "test", :contracts => [Contract.new(:developer_id => 7)]) assert_equal [7], Company.joins(:contracts).pluck(:developer_id) end + + def test_plucks_with_ids + assert_equal Company.all.map(&:id), Company.ids + end end |