diff options
Diffstat (limited to 'activerecord/lib/active_record/relation/finder_methods.rb')
-rw-r--r-- | activerecord/lib/active_record/relation/finder_methods.rb | 30 |
1 files changed, 20 insertions, 10 deletions
diff --git a/activerecord/lib/active_record/relation/finder_methods.rb b/activerecord/lib/active_record/relation/finder_methods.rb index a4280c5f33..8b114c6bdf 100644 --- a/activerecord/lib/active_record/relation/finder_methods.rb +++ b/activerecord/lib/active_record/relation/finder_methods.rb @@ -145,15 +145,21 @@ module ActiveRecord # # [#<Person id:4>, #<Person id:3>, #<Person id:2>] def last(limit = nil) - if limit - if order_values.empty? && primary_key - order(arel_attribute(primary_key).desc).limit(limit).reverse - else - to_a.last(limit) - end - else - find_last - end + return find_last(limit) if loaded? || limit_value + + result = limit(limit || 1) + result.order!(arel_attribute(primary_key)) if order_values.empty? && primary_key + result = result.reverse_order! + + limit ? result.reverse : result.first + rescue ActiveRecord::IrreversibleOrderError + ActiveSupport::Deprecation.warn(<<-WARNING.squish) + Finding a last element by loading the relation when SQL ORDER + can not be reversed is deprecated. + Rails 5.1 will raise ActiveRecord::IrreversibleOrderError in this case. + Please call `to_a.last` if you still want to load the relation. + WARNING + find_last(limit) end # Same as #last but raises ActiveRecord::RecordNotFound if no record @@ -330,7 +336,7 @@ module ActiveRecord end # This method is called whenever no records are found with either a single - # id or multiple ids and raises a ActiveRecord::RecordNotFound exception. + # id or multiple ids and raises an ActiveRecord::RecordNotFound exception. # # The error message is different depending on whether a single id or # multiple ids are provided. If multiple ids are provided, then the number @@ -578,5 +584,9 @@ module ActiveRecord find_nth_with_limit(index, limit) end end + + def find_last(limit) + limit ? to_a.last(limit) : to_a.last + end end end |