Created an unscope method for removing relations from a chain of

relations. Specific where values can be unscoped, and the unscope method
still works when relations are merged or combined.

1 files changed, 16 insertions, 0 deletions

diff --git a/activerecord/CHANGELOG.md b/activerecord/CHANGELOG.md
index 2eaf388095..d265f04562 100644
--- a/activerecord/CHANGELOG.md
+++ b/activerecord/CHANGELOG.md
@@ -1,5 +1,21 @@
 ## Rails 4.0.0 (unreleased) ##
 
+*   Added functionality to unscope relations in a relations chain. For
+    instance, if you are passed in a chain of relations as follows:
+
+        Posts.select(:name => "John").order('id DESC') 
+
+    but you want to get rid of order, then this feature allows you to do:
+
+        Posts.select(:name => "John").order("id DESC").unscope(:order)
+            == Posts.select(:name => "John")
+
+    The .unscope() function is more general than the .except() method because
+    .except() only works on the relation it is acting on. However, .unscope()
+    works for any relation in the entire relation chain.
+
+    *John Wang*
+
 *   Postgresql timestamp with time zone (timestamptz) datatype now returns a
     ActiveSupport::TimeWithZone instance instead of a string