diff options
| -rw-r--r-- | activerecord/lib/active_record/relation/finder_methods.rb | 20 | ||||
| -rw-r--r-- | activerecord/test/cases/finder_test.rb | 6 |
2 files changed, 24 insertions, 2 deletions
diff --git a/activerecord/lib/active_record/relation/finder_methods.rb b/activerecord/lib/active_record/relation/finder_methods.rb index 1ceb1949a4..9fd8b49ffb 100644 --- a/activerecord/lib/active_record/relation/finder_methods.rb +++ b/activerecord/lib/active_record/relation/finder_methods.rb @@ -60,6 +60,9 @@ module ActiveRecord where(*args).first! end + # Find the first record (or first N records if a parameter is supplied). + # If no order is defined it will order by primary key. + # # Examples: # # Person.first # returns the first object fetched by SELECT * FROM people @@ -67,7 +70,15 @@ module ActiveRecord # Person.where(["user_name = :u", { :u => user_name }]).first # Person.order("created_on DESC").offset(5).first def first(limit = nil) - limit ? limit(limit).to_a : find_first + if limit + if order_values.empty? && primary_key + order("#{quoted_table_name}.#{quoted_primary_key} ASC").limit(limit).to_a + else + limit(limit).to_a + end + else + find_first + end end # Same as +first+ but raises <tt>ActiveRecord::RecordNotFound</tt> if no record @@ -319,7 +330,12 @@ module ActiveRecord if loaded? @records.first else - @first ||= limit(1).to_a[0] + @first ||= + if order_values.empty? && primary_key + order("#{quoted_table_name}.#{quoted_primary_key} ASC").limit(1).to_a[0] + else + limit(1).to_a[0] + end end end diff --git a/activerecord/test/cases/finder_test.rb b/activerecord/test/cases/finder_test.rb index 29469c42ed..fdc7fad40a 100644 --- a/activerecord/test/cases/finder_test.rb +++ b/activerecord/test/cases/finder_test.rb @@ -163,6 +163,12 @@ class FinderTest < ActiveRecord::TestCase end end + def test_first_have_primary_key_order_by_default + expected = topics(:first) + expected.touch # PostgreSQL changes the default order if no order clause is used + assert_equal expected, Topic.first + end + def test_model_class_responds_to_first_bang assert Topic.first! Topic.delete_all |