BEGIN
DECLARE $start, $end INT DEFAULT 1;
LOOP
SET $start = LOCATE("<", $str, $start);
IF (!$start) THEN RETURN $str; END IF;
SET $end = LOCATE(">", $str, $start);
IF (!$end) THEN SET $end = $start; END IF;
SET $str = INSERT($str, $start, $end - $start + 1, "");
END LOOP;
END