From d51e7f8252269492a511a9eb41f2832646a44248 Mon Sep 17 00:00:00 2001 From: Rick Olson Date: Wed, 25 Jul 2007 03:09:21 +0000 Subject: Ensure that has_many :through associations use a count query instead of loading the target when #size is called. Closes #8800 [lifo] git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@7237 5ecf4fe2-1ee6-0310-87b1-e25e094e27de --- .../lib/active_record/associations/has_many_through_association.rb | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'activerecord/lib/active_record') diff --git a/activerecord/lib/active_record/associations/has_many_through_association.rb b/activerecord/lib/active_record/associations/has_many_through_association.rb index ebe1be04e5..ec093548da 100644 --- a/activerecord/lib/active_record/associations/has_many_through_association.rb +++ b/activerecord/lib/active_record/associations/has_many_through_association.rb @@ -96,6 +96,13 @@ module ActiveRecord end end + # Returns the size of the collection by executing a SELECT COUNT(*) query if the collection hasn't been loaded and + # calling collection.size if it has. If it's more likely than not that the collection does have a size larger than zero + # and you need to fetch that collection afterwards, it'll take one less SELECT query if you use length. + def size + loaded? ? @target.size : count + end + # Calculate sum using SQL, not Enumerable def sum(*args, &block) calculate(:sum, *args, &block) -- cgit v1.2.3