1 files changed, 22 insertions, 0 deletions
diff --git a/lib/gitlab/sql/except.rb b/lib/gitlab/sql/except.rb
new file mode 100644
index 00000000000..82cbfa8d4ab
--- /dev/null
+++ b/lib/gitlab/sql/except.rb
@@ -0,0 +1,22 @@
+# frozen_string_literal: true
+
+module Gitlab
+  module SQL
+    # Class for building SQL EXCEPT statements.
+    #
+    # ORDER BYs are dropped from the relations as the final sort order is not
+    # guaranteed any way.
+    #
+    # Example usage:
+    #
+    #     except = Gitlab::SQL::Except.new([user.projects, user.personal_projects])
+    #     sql    = except.to_sql
+    #
+    #     Project.where("id IN (#{sql})")
+    class Except < SetOperator
+      def self.operator_keyword
+        'EXCEPT'
+      end
+    end
+  end
+end