1 files changed, 4 insertions, 0 deletions
diff --git a/lib/arel/visitors/to_sql.rb b/lib/arel/visitors/to_sql.rb
index 5319aeb418..73319364d5 100644
--- a/lib/arel/visitors/to_sql.rb
+++ b/lib/arel/visitors/to_sql.rb
@@ -142,6 +142,10 @@ key on UpdateManager using UpdateManager#key=
         'DISTINCT'
       end
 
+      def visit_Arel_Nodes_DistinctOn o
+        raise NotImplementedError, 'DISTINCT ON not implemented for this db'
+      end
+
       def visit_Arel_Nodes_With o
         "WITH #{o.children.map { |x| visit x }.join(', ')}"
       end