mysql_num_rows(): supplied argument is not a valid MySQL result resource

[jjfletch]

Anyone understand why I'm getting this error message? Here's the code snippet:

...

if ($fn && $ln && $e && $u && $p && $bt && $h) {

            $query = "SELECT user_id FROM users WHERE username='$u'";
            $result = @mysql_query ($query);

            if (mysql_num_rows($result) == 0) {

            $query = "INSERT INTO users (UserName, UserEmail, FirstName, LastName, IPAddress, BlogTitle, password, RegDate) 
                      VALUES ('$u','$e','$fn','$ln','$h','$bt',PASSWORD('$p'), NOW())";
            $result = @mysql_query($query);

...

[devinemke]

replace this:

$result = @mysql_query ($query);

with this:

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

and look at the output to see what's going wrong.