mysql - How to get largest number in SQL -


i have code varchar field want auto-increment if user doesn't provide code of own. example:

`code` - '5' - '8' - 's987' - '981a'

in case, largest (pure) number 8, want autoincrement 9. how this? so, want to:

(1) largest number (even though it's stored varchar) in table. in above entries, 8 largest number, since s987 , 981a not valid numbers. (2) add 1 number new autoincrement number.

try this

select max(cast(code unsigned))+1 mytable code regexp '[0-9]+';

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