UPDATE vn.shelving 
SET isPrinted = TRUE
	WHERE LEFT (code, 2) IN (
		SELECT DISTINCT LEFT(code,2)
			FROM vn.shelving
			WHERE isPrinted
				AND code REGEXP '^[A-Za-z]{2}[0-9]'
			ORDER BY code)
		AND code REGEXP '^[A-Za-z]{2}[0-9]'