CREATE OR REPLACE FUNCTION ensure_object_connection(integer, integer)
RETURNS BOOLEAN AS '
DECLARE
  create BOOLEAN;
BEGIN
  PERFORM * FROM object_connection
  WHERE origin_id=$1 AND target_id=$2;
  create := NOT FOUND;
  IF create THEN
    INSERT INTO object_connection (origin_id, target_id) VALUES ($1, $2);
  END IF;
  RETURN create;
END;
' LANGUAGE plpgsql;