[Resolved] if user exists

[fean0r]

$sql = "INSERT INTO " . "user" . " VALUES('', 'none', 'user', '" . addslashes($_POST['username']) . "', '" . md5($_POST['password']) . "', '" . addslashes($_POST['user_clan']) . "', '" . addslashes($_POST['user_web']) . "', '" . addslashes($_POST['msnm']) . "', '" . addslashes($_POST['yahoo']) . "', '" . addslashes($_POST['icq']) . "', '" . addslashes($_POST['user_email']) . "', '" . addslashes($_POST['user_info']) . "', 'none', 'none', 'none', 'none', 'none', 'none', 'none', 'none', 'none', 'none', 'none', 'none', 'none', 'none', 'none', 'none', 'none')";
if(!($result = mysql_query($sql))) {
    die(mysql_error());
} else {

How do I create an error when the user name has been taken?

Thanks

[Natty_Dreadlock]

first perform this query:

$sql = "SELECT * FROM user WHERE username='" . $_POST["username"] . "'";
if(!($result = mysql_query($sql))) { 
    die(mysql_error()); 
} 
else 
{
    if(mysql_num_rows($result) > 0)
          die("Username already exists");
    else
       // do your insert etc.
}

hth

[ahundiak]

CREATE UNIQUE INDEX user_i1 ON user(user);

With an unique index, you can be certain that you will never get two records with the same user value.

[fean0r]

cheers that coded worked a treat..

[simwiz]

I was just wondering what the >0 meant ? in the if statement

if(mysql_num_rows($result) > 0)
die("Username already exists");

I can understand the query ect but not the if statement which controls the validation.

thank you in advance.

[Natty_Dreadlock]

hi,

I was just wondering what the >0 meant ? in the if statement

if(mysql_num_rows($result) > 0)
die("Username already exists");

the checks whether there is at least one row in the result (then there is already a user of the name) - here u could leave out the > 0 since mysql_num_rows only returns positive integers so the if query would be true for all numbers except zero... but i think >0 is clearer because it shows that the condition refers to a positive row count ...
hth undestanding