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authorZachary Scott <e@zzak.io>2014-06-16 12:53:37 -0700
committerZachary Scott <e@zzak.io>2014-06-16 12:53:37 -0700
commitc730ae9b7788ce58fef1b62340271b3420ce962e (patch)
tree84aa69712eb0d121188da6e80a2a2d01e606e0f8
parent5b368010f64106f7b87a4306b41adcefa856ab67 (diff)
parentae1b42c339a80794fb6f641e9a290dbfff72138e (diff)
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Merge pull request #15756 from aditya-kapoor/add-api-doc-for-querying
[ci skip] add API doc for AR Group.
-rw-r--r--activerecord/lib/active_record/relation/calculations.rb10
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