Is it possible to make auto_increment relative to another field?

Question

MySQL

Now the table looks like this:

`id` = 1, `id_user` = 2
`id` = 2, `id_user` = 2
`id` = 3, `id_user` = 1

Is it possible to auto_increment relative to the `id_user` field so that it is?

`id_user` = 2, `id` = 1
`id_user` = 2, `id` = 2
`id_user` = 1, `id` = 1

Answer 1

myISAM only
MyISAM Notes
For MyISAM tables, you can specify AUTO_INCREMENT on a secondary column in a multiple-column index. In this case, the generated value for the AUTO_INCREMENT column is calculated as MAX(auto_increment_column) + 1 WHERE prefix=given-prefix. This is useful when you want to put data into ordered groups.

Answer 2

By means of mysql - no.