Consistently use LOWER() for uniqueness validations (rather than mixing with UPPER()) so the database can always use a functional index on the lowercased column. Closes #6495.

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@5434 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

2 files changed, 4 insertions, 2 deletions

diff --git a/activerecord/CHANGELOG b/activerecord/CHANGELOG
index ce8c1558e2..52068e461e 100644
--- a/activerecord/CHANGELOG
+++ b/activerecord/CHANGELOG
@@ -1,5 +1,7 @@
 *SVN*
 
+* Consistently use LOWER() for uniqueness validations (rather than mixing with UPPER()) so the database can always use a functional index on the lowercased column.  #6495 [Si]
+
 * SQLite: fix calculations workaround, remove count(distinct) query rewrite, cleanup test connection scripts.  [Jeremy Kemper]
 
 * SQLite: count(distinct) queries supported in >= 3.2.6.  #6544 [Bob Silva]
diff --git a/activerecord/lib/active_record/validations.rb b/activerecord/lib/active_record/validations.rb
index 606362eacd..7d77f35a7a 100755
--- a/activerecord/lib/active_record/validations.rb
+++ b/activerecord/lib/active_record/validations.rb
@@ -533,8 +533,8 @@ module ActiveRecord
             condition_sql = "#{record.class.table_name}.#{attr_name} #{attribute_condition(value)}"
             condition_params = [value]
           else
-            condition_sql = "UPPER(#{record.class.table_name}.#{attr_name}) #{attribute_condition(value)}"
-            condition_params = [value.upcase]
+            condition_sql = "LOWER(#{record.class.table_name}.#{attr_name}) #{attribute_condition(value)}"
+            condition_params = [value.downcase]
           end
           if scope = configuration[:scope]
             Array(scope).map do |scope_item|