Това е най-ясният начин
UPDATE test
SET col2 = CASE col1
WHEN 'test1' THEN 1
WHEN 'test2' THEN 3
WHEN 'test3' THEN 5
END,
colx = CASE col1
WHEN 'test1' THEN 'xx'
WHEN 'test2' THEN 'yy'
WHEN 'test3' THEN 'zz'
END
WHERE col1 IN ('test1','test2','test3')
