Mysql / php - 身份证号码达到9999并从0001开始计算

Question

I have a PHP website which takes customer applications. Each application is given an ID number which is incremental.

Recently the site reached application id number 9999 but instead of continuing on to 10000 it reverted back to 0001

Any ideas why this happened - perhaps some kind of php or mysql setting, range or limit?!

Thanks in advance

Answer 1

yes there was some forming applied in the php to limit to 4 digits (0000) so when it reached 10000 it was cutting off the first 1. This was causing it to appear as 0001 etc in the backend and other places...

As a consequence it was also sending out the cut version of the id nmber in emails to applicants and causing all sorts of mess lol!

Took a while to find the right file because the original coder is not available!

Thanks to all.