1 files changed, 26 insertions, 0 deletions
diff --git a/lib/arel/relations/utilities/compound.rb b/lib/arel/relations/utilities/compound.rb
new file mode 100644
index 0000000000..a77099e0de
--- /dev/null
+++ b/lib/arel/relations/utilities/compound.rb
@@ -0,0 +1,26 @@
+module Arel
+  class Compound < Relation
+    attr_reader :relation
+    hash_on :relation
+    delegate :joins, :wheres, :join?, :inserts, :taken,
+             :skipped, :name, :aggregation?, :column_for,
+             :engine, :table, :table_sql,
+             :to => :relation
+    
+    def attributes
+      @attributes ||= relation.attributes.collect { |a| a.bind(self) }
+    end
+    
+    def wheres
+      @wheres ||= relation.wheres.collect { |w| w.bind(self) }
+    end
+    
+    def groupings
+      @groupings ||= relation.groupings.collect { |g| g.bind(self) }
+    end
+    
+    def orders
+      @orders ||= relation.orders.collect { |o| o.bind(self) }
+    end
+  end
+end
+\ No newline at end of file