how to select the max value in mysql in varchar field

Question

I have one mysql table, in that table contain varchar field. I want to get the max value from the table.

My Table -

My SQL QUERY -

SELECT Max(CAST(test as SIGNED)) as a FROM testtable;

Wanted Output-

G450

how to select the max value in mysql in varchar field?

Answer 1

If your data always has single character followed by integer, you can use the following:

SELECT * FROM testtable WHERE substring(test,2)=(SELECT MAX(CAST(SUBSTRING(test,2) AS SIGNED)) FROM testtable);

This will return all rows with the character followed by the max integer - ie if you have G540 and X540, it'll return both.

Answer 2

SELECT CONCAT('G' , MAX(0+SUBSTRING(test,2))) FROM TABLE_NAME