Error handling in mysql

[Anon]

hi,
i am working on a db program. in the enterance page it is asking user to enter a password for mysql.
and in the second page it is trying to connect to mysql with this password

i want to bring the user to the error page (err.php) when the password is wrong
and when the passwd is true i want to bring the user to the success page (index_main.php)

i am trying a argument like that:

if(!($dp=mysql_connect("localhost","root",$passwd)))
{
header("Location:err.php");
}
else {
header("Location:index_main.php");
}
note: in here $passwd is the password taken from the enterance page...

when i try to run it and enter a wrong password it doesn't go to err.php
instead of going err.php it is viewing mysql error message

what could i do?
thanks from now for your answers

best regards

[foxden]

Why not validate the username/password with PHP and enclose the MySQL infor in an if/else clause within PHP?

[pcc0d3r]

sorry but i couldn't undestand you?
english is not my mother language 🙁
can you explain it to me with a basic example...

[foxden]

Here is how I handle user validation:

<?

$login = "<p><form method=\"post\" action=\"$PHP_SELF\">
Username:<br>
<input type=\"text\" name=\"username\" value=\"$username\" size=\"10\" maxlength=\"25\">
Password:<br>
<input type=\"password\" name=\"password\" value=\"$password\" size=\"10\" maxlength=\"15\">
<input type=\"hidden\" name=\"my_login\" value=\"yes\">
<input type=\"submit\" name=\"submit_login\" value=\"Log in\">
</form>
</p>
";

     if ($my_login == "yes")
          {

                       $connection = @mysql_connect("localhost", "db_name", "password") or
                         die("Couldn't connect to $db_name");

           $db = @mysql_select_db(db_name,$connection) or
                 die("Couldn't select db_name");


            $sql = "select * from table_name where username = \"$username\"
                                              and password = password(\"$password\")";


               $result = @mysql_query($sql,$connection) or
                         die(mysql_error());     

                $num = @mysql_numrows($result);  

                   if ($num !=0)
                    {
                      header("Location:index_main.php"); 
                    }
                  else
                    {
                      header("Location:err.php");  
                    }

            }

if ($my_login != "yes")
{
echo $login
}

?>

[[deleted]]

That would get the password from mysql, but he wants to enter a password to get into mysql in the first place.

Most likely his problem is that mysql_connec() will print an error message.
After printing that message, PHP will refuse to send the header() because it alreay sent output:
"Cannot send headers, output already started at line bladebla"

try this:

// use the @ to tell mysql it should to print any error messages
if(!($dp=@mysql_connect("localhost","root",$passwd)))
{
// Connection failed
header("Location:err.php");
}
else {
// Connection ok.
header("Location:index_main.php");
}

Note: this will only tell you that the connection failed, it will not tell you why!!