[Resolved] MySQL Autonumber

[areid]

Hi I am new to the forum and I hopefully have a simple question...

Is there a way that I can create an auto number in MySQL or with PHP code that will put a letter in front of the number, such as...

W0001
W0002
W0003
W0004

Or..

W1
W2
W3
W4

Either one works, it really doesn’t matter, which ever one is easier.

If there is anyone that could help me out or give me some suggestions it would be much appreciated!

[drawmack]

auto_number fields are numeric only. However you could create your own auto_number routine like this:

<?php
    function gen_next_autonum($table='drawmack',$field = 'isGod',$let='a') {
        $sql = "SELECT MAX($field) FROM $table";
        $query = mysql_query($sql);

   //handle those pesky empty tables
    if(mysql_num_rows($query) < 1) {
        return $let . '1';
    } //end if

    $result = mysql_result($query,0,0);
    $num = intval(substr($result,1));
    $num++;
    return $let . $num;
} //end gen_next_autonum
?>

[Lars_Berg]

That is a no good function. It will not work in a multiuser environment.

[drawmack]

sure it will if you lock the table properly outside the function.

[Lars_Berg]

Locking tables on the client side is another thing to be avoided.

areid:

Use an auto_increment. If you wish to show the values with a prefix that is can easily be handled when retrieving data.

[TheDefender]

Read this thread regarding this very thing. Not sure if that author started it because of this question, but a good read nevertheless.