string passthrough for "group by"

2 files changed, 7 insertions, 1 deletions

diff --git a/lib/arel/relations/relation.rb b/lib/arel/relations/relation.rb
index 8c56a0cdcc..cd58f0f15c 100644
--- a/lib/arel/relations/relation.rb
+++ b/lib/arel/relations/relation.rb
@@ -11,7 +11,7 @@ module Arel
         (joins(self)                                                                                    unless joins(self).blank? ),
         ("WHERE     #{selects.collect { |s| s.to_sql(Sql::WhereClause.new(self)) }.join("\n\tAND ")}"   unless selects.blank?     ),
         ("ORDER BY  #{orders.collect { |o| o.to_sql(Sql::OrderClause.new(self)) }.join(', ')}"          unless orders.blank?      ),
-        ("GROUP BY  #{groupings.collect(&:to_sql)}"                                                     unless groupings.blank?   ),
+        ("GROUP BY  #{groupings.collect { |g| g.to_sql(Sql::GroupClause.new(self)) }.join(', ')}"       unless groupings.blank?   ),
         ("LIMIT     #{taken}"                                                                           unless taken.blank?       ),
         ("OFFSET    #{skipped}"                                                                         unless skipped.blank?     )
       ].compact.join("\n"), name
diff --git a/lib/arel/sql/formatters.rb b/lib/arel/sql/formatters.rb
index 96bab2495c..5eab65726e 100644
--- a/lib/arel/sql/formatters.rb
+++ b/lib/arel/sql/formatters.rb
@@ -44,6 +44,12 @@ module Arel
       end
     end
     
+    class GroupClause < PassThrough
+      def attribute(attribute)
+        "#{quote_table_name(name_for(attribute.original_relation))}.#{quote_column_name(attribute.name)}"
+      end
+    end
+    
     class WhereCondition < Formatter
       def attribute(attribute)
         "#{quote_table_name(name_for(attribute.original_relation))}.#{quote_column_name(attribute.name)}"