使用php为mysql数据库生成随机id

Question

I have searched high and low for an answer with no avail.

I am trying to insert a random id number for my users between 9999,99999999. Problem is they have to be unique. I have everything set up but with an auto increment set for the id. I figured I will keep the auto increment field and just add another row for the unique id.

This is what I got so far:

$id = mt_rand(9999,99999999);

    $query = "SELECT * FROM accounts";

    $result = mysql_query($query) or die(mysql_error());

    while($account = mysql_fetch_array($result)){

        if ($id == $account['id']){

    $id = mt_rand(9999,99999999);

    } else {

    $sql = "INSERT INTO accounts (id, username, email, password, sex)
    VALUES ('$id', '$username', '$email', '$password', '$sex')";
    mysql_query($sql);}}

Now I figured if I create a random number, check the database if it exists create another, else insert it, but it is not working, if it a simple solution I apologise.

Thanks again :)

Answer 1

this may seem like a silly answer:

If you are already using auto_increment on a unique key, there is not a need to add another unique key