Mysql the highest of 1 row

Question

Is poslbe too big value from string?

IE I have 3 days as columns with a timestamp value, can I get the highest value?

Answer 1

GREATEST () may be what you want:

http://dev.mysql.com/doc/refman/5.1/en/comparison-operators.html#function_greatest

Answer 2

SELECT MAX(column1,column2,cloumn3) FROM ...