I have a table `member`. I want to make an user id using auto increment.
I have tried using the following:

```
SET new.user_id = CONCAT(new.name, LPAD((SELECT AUTO_INCREMENT FROM 
information_schema.TABLES WHERE
TABLE_SCHEMA = DATABASE() AND TABLE_NAME = 'member'),3,'0'));

```

But when I inserted a new member, i've got an error message `user_id cannot be null` and the data wasn't added. I want the user id will shown like `jos001` as an primary key.

Please help me.. how to make it happen?