1 files changed, 6 insertions, 0 deletions
diff --git a/lib/arel/engines/memory/predicates.rb b/lib/arel/engines/memory/predicates.rb
index dd2559c70f..f87bf68357 100644
--- a/lib/arel/engines/memory/predicates.rb
+++ b/lib/arel/engines/memory/predicates.rb
@@ -10,6 +10,12 @@ module Arel
       def operator; :== end
     end
 
+    class Not < Binary
+      def eval(row)
+        operand1.eval(row) != operand2.eval(row)
+      end
+    end
+
     class GreaterThanOrEqualTo < Binary
       def operator; :>= end
     end