php - MySQL InnoDB AUTO_INCREMENT secondary column -
i making system users can upload file want, , not use execute kind of code. part of that, rename every file, , store original name in mysql table. table contains id of user uploaded it, , unique id of upload. doing this: create table `uploads` ( `user_id` int(11) not null, `upload_id` int(11) not null auto_increment, `original_name` varchar(30) not null, `mime_type` varchar(30) not null, `name` varchar(50) not null, primary key (`user_id`, `upload_id`) ) engine=myisam; this means have unique combination of user_id , upload_id, , every users first upload has id of 1. want use foreign key user_id, if delete user, uploads deleted. means have in innodb. how go that, since above setup works in myisam. my users table (wich user_id from) looks this: create table `".database."`.`users` ( `user_id` int not null auto_increment primary key, `username` varchar(30) not null, `email` varchar(50) not null, `password` char(128) not null...