1 files changed, 6 insertions, 0 deletions
diff --git a/activerecord/lib/arel/visitors/ibm_db.rb b/activerecord/lib/arel/visitors/ibm_db.rb
index 0a06aef60b..73166054da 100644
--- a/activerecord/lib/arel/visitors/ibm_db.rb
+++ b/activerecord/lib/arel/visitors/ibm_db.rb
@@ -10,6 +10,12 @@ module Arel # :nodoc: all
           collector = visit o.expr, collector
           collector << " ROWS ONLY"
         end
+
+        def is_distinct_from(o, collector)
+          collector << "DECODE("
+          collector = visit [o.left, o.right, 0, 1], collector
+          collector << ")"
+        end
     end
   end
 end