Как сделать CASE WHEN THEN для нескольких значений?

UPDATE `col` SET
`nul` = CASE
WHEN (`attr1`,`attr2`) = ('param1','otv1') THEN '1'
WHEN (`attr1`,`attr2`) = ('param1','otv2') THEN '2'
WHEN (`attr1`,`attr2`) = ('param1','otv3') THEN '3'
END,
`bul` = CASE
WHEN (`attr1`,`attr2`) = ('param1','otv1') THEN '1'
WHEN (`attr1`,`attr2`) = ('param1','otv2') THEN '2'
WHEN (`attr1`,`attr2`) = ('param1','otv3') THEN '3'
END
WHERE (`attr1`,`attr2`) IN (('param1','otv1'),('param1','otv2'),('param1','otv3'))