Implement ActiveRecord#reset_counter_cache

[#1211 state:committed]

Signed-off-by: Jeremy Kemper <jeremy@bitsweat.net>

1 files changed, 18 insertions, 0 deletions

diff --git a/activerecord/lib/active_record/base.rb b/activerecord/lib/active_record/base.rb
index 056f29f029..e04684dc43 100755
--- a/activerecord/lib/active_record/base.rb
+++ b/activerecord/lib/active_record/base.rb
@@ -967,6 +967,24 @@ module ActiveRecord #:nodoc:
         connection.select_value(sql, "#{name} Count").to_i
       end
 
+      # Reset a counter cache for all records.
+      #
+      # ==== Parameters
+      #
+      # * +association_name+ - The name of of the association counter cache to reset
+      #
+      # ==== Examples
+      #   # For all Post records reset the comments_count
+      #   Post.reset_counter_cache(:comments)
+      def reset_counter_cache(association)
+        child_class = reflect_on_association(association).klass
+        counter_name = child_class.reflect_on_association(self.name.downcase.to_sym).counter_cache_column
+
+        find_each do |object|
+          connection.update("UPDATE #{quoted_table_name} SET #{connection.quote_column_name(counter_name)} = #{object.send(association).count} WHERE #{connection.quote_column_name(primary_key)} = #{quote_value(object.id)}", "#{name} UPDATE")
+        end
+      end
+
       # A generic "counter updater" implementation, intended primarily to be
       # used by increment_counter and decrement_counter, but which may also
       # be useful on its own. It simply does a direct SQL update for the record