diff options
Diffstat (limited to 'activerecord/lib/active_record/counter_cache.rb')
| -rw-r--r-- | activerecord/lib/active_record/counter_cache.rb | 18 |
1 files changed, 10 insertions, 8 deletions
diff --git a/activerecord/lib/active_record/counter_cache.rb b/activerecord/lib/active_record/counter_cache.rb index c53b7b3e78..81f92db271 100644 --- a/activerecord/lib/active_record/counter_cache.rb +++ b/activerecord/lib/active_record/counter_cache.rb @@ -79,16 +79,17 @@ module ActiveRecord where(primary_key => id).update_all updates.join(', ') end - # Increment a number field by one, usually representing a count. + # Increment a numeric field by one, via a direct SQL update. # - # This is used for caching aggregate values, so that they don't need to be computed every time. - # For example, a DiscussionBoard may cache post_count and comment_count otherwise every time the board is - # shown it would have to run an SQL query to find how many posts and comments there are. + # This method is used primarily for maintaining counter_cache columns used to + # store aggregate values. For example, a DiscussionBoard may cache posts_count + # and comments_count to avoid running an SQL query to calculate the number of + # posts and comments there are each time it is displayed. # # ==== Parameters # # * +counter_name+ - The name of the field that should be incremented. - # * +id+ - The id of the object that should be incremented. + # * +id+ - The id of the object that should be incremented or an Array of ids. # # ==== Examples # @@ -98,14 +99,15 @@ module ActiveRecord update_counters(id, counter_name => 1) end - # Decrement a number field by one, usually representing a count. + # Decrement a numeric field by one, via a direct SQL update. # - # This works the same as increment_counter but reduces the column value by 1 instead of increasing it. + # This works the same as increment_counter but reduces the column value by + # 1 instead of increasing it. # # ==== Parameters # # * +counter_name+ - The name of the field that should be decremented. - # * +id+ - The id of the object that should be decremented. + # * +id+ - The id of the object that should be decremented or an Array of ids. # # ==== Examples # |