Variantenpreise abgleichen

UPDATE oxarticles B ,(
SELECT oxactive, oxparentid,MIN( oxprice ) AS min ,MAX( oxprice ) AS max
FROM oxarticles WHERE oxactive = 1
GROUP BY oxparentid
) AS A
SET B.oxvarminprice = CASE WHEN A.min IS NULL THEN B.oxprice ELSE A.min END,
B.oxvarmaxprice = CASE WHEN A.max IS NULL THEN B.oxprice ELSE A.max END
WHERE B.oxid = A.oxparentid