ask about php summarize 01 + 01 = 02

Question

I want to make a id in database

id_user => data type 'varchar'

I want my id to start from 00, 01, 02, and so on. And to make new id, I count the all the rows, and the result from count will be added by 01.

Example:

$id=array(00,01,02);
$count_exist_id = $count($id)
$new_id= '00' + $count_exist_id

and I hope the new id must be '03' and it will be store to database in table user column id_user

Answer 1

You can use INT(x) ZEROFILL, to add 0 before the number. '1' => '001'

With INT ZEROFILL, you have AUTO_INCREMENT. ;)

CREATE TABLE user (
   id_user INT(8) UNSIGNED ZEROFILL NOT NULL AUTO_INCREMENT, 
   PRIMARY KEY(id_user)
);

If you use UNSIGNED, you optimize your table, and you save one BIT, to get bigger number.

See :

• What is the benefit of zerofill in MySQL?
• How can I set autoincrement format to 0001 in MySQL?
• What does "unsigned" in MySQL mean and when to use it?