Calculate next Primary Key - of specific format

Question

I have a table which holds a list of IDs, and various other columns such as IDName.

The Primary Key of the table is the ID itself, however it does not auto_increment

Answer 1

Unless your application is in very high demand the number of collisions will be very low. So I would simply retry if a key error is raised.

select coalesce(max(id), 27770000) + 1
from myTable
where id / 10000 = 2777

The coalesce is there in case that level/code does not yet exist.