Create an unique ID number after submit form

in order to do this use

 AUTO_INCREMENT PRIMARY KEY 

while you define your table. Your table should be something like this:

CREATE TABLE `order` (
            `order_id` INT(11) UNSIGNED AUTO_INCREMENT PRIMARY KEY,
            `user_group_id` INT(11) UNSIGNED NOT NULL,
            `status` BIT,
            `meta` VARCHAR ( 255 ),
            `value` TEXT,
            `update_time` TIMESTAMP
            )DEFAULT CHARSET = utf8;

remember that you could change other columns, the important one is order_id which is auto increment