Question

Can you get the true MIN/MAX of a date/time using this on MySQL?

MAX(CONCAT(`Date`, ' ', `Time`)) 

Considering this is a string?

I want to do this for the reason that I am working with a database where the date field and the time field is separated.

I tried doing this and it seems fine however I am wondering if there is a better way to do this that would not require separate queries.

EDIT:

Date and Time fields are in native MySQL format.

Answer 1

Assuming your date and time parts are already in the native MySQL format YYYY-mm-dd and hh:mm:ss, you can CAST() the concatenated result to a DATETIME, after which normal DATETIME collation will apply.

SELECT CAST(CONCAT(DATE(NOW()), ' ', TIME(NOW())) AS DATETIME);

+---------------------------------------------------------+
| CAST(CONCAT(DATE(NOW()), ' ', TIME(NOW())) AS DATETIME) |
+---------------------------------------------------------+
| 2011-11-06 10:42:42                                     |
+---------------------------------------------------------+