How to properly sort multiple ORDER BY DESC conditions?

Question

MySQL

SELECT * FROM `serial` ORDER BY `serial`.`season` DESC, `serial`.`episode` DESC LIMIT 10

The first parameter is normal, but the second parameter is not in numerical order for some reason. How to fix it ?

Answer 1

Most likely, the field has a text type, not a numeric type, which is why it is sorted as text.
Use Explicit Conversion

ORDER BY ... CAST(`serial`.`episode` AS UNSIGNED) DESC

Of course, the index will not work with such sorting.

Answer 2

Probably because episode is not a numeric type?