diff options
| -rw-r--r-- | activerecord/lib/active_record/relation/calculations.rb | 10 |
1 files changed, 9 insertions, 1 deletions
diff --git a/activerecord/lib/active_record/relation/calculations.rb b/activerecord/lib/active_record/relation/calculations.rb index 028e4d80ab..316a59e0bb 100644 --- a/activerecord/lib/active_record/relation/calculations.rb +++ b/activerecord/lib/active_record/relation/calculations.rb @@ -19,7 +19,15 @@ module ActiveRecord # # Person.group(:city).count # # => { 'Rome' => 5, 'Paris' => 3 } - # + # + # If +count+ is used with +group+ for multiple columns, it returns a Hash whose + # keys are an array containing the individual values of each column and the value + # of each key would be the +count+. + # + # Article.group(:status, :category).count + # # => {["draft", "business"]=>10, ["draft", "technology"]=>4, + # ["published", "business"]=>0, ["published", "technology"]=>2} + # # If +count+ is used with +select+, it will count the selected columns: # # Person.select(:age).count |