mysql_num_rows problem

[hughes]

Hi, I keep getting an error result saying:

Warning: mysql_num_rows(): supplied argument is not a valid MySQL result resource in *** on line 9

Warning: Cannot modify header information - headers already sent by (output started at \***:9) in **** on line 12

I'm pretty new to PHP so I'm thinking its a problem with syntax. Any help is appreciated. Code is below.

<?PHP

$ni = trim($_POST['ni']);

require 'db_connect.php';

$sql = "SELECT * FROM $db_table WHERE ni = '$ni'";
$query = "mysql_query($sql) or die (mysql_error())";
if (mysql_num_rows($query) < 1) {

require 'db_close.php';
header("location: DESIRED LOCATION");
}
else{
require 'db_close.php';
header("Location: EXIT ");
}

?>

[mcibor]

This should work:

<?php

$ni = trim($_POST['ni']);

require 'db_connect.php';

$sql = "SELECT * FROM $db_table WHERE ni = '$ni'";
$query = mysql_query($sql) or die (mysql_error());//No quotes here!
if (mysql_num_rows($query) < 1) {

require 'db_close.php';
header("location: http://www.example.com/go_on.html");//here should be url, no text
}
else{
require 'db_close.php';
header("Location: http://www.example.com/exit.html");
}
?>

Make sure, that before <? there is nothing, not even space!

Best regards
Michal Cibor

[dreamcatcher]

Both of the errors are related. You cannot send data to the browser before you call the header function. Because a message is being sent to due to the num rows error, this is why you are getting the headers not sent error.

Apply the fix shown by mcibor and it should be fine.

dc

[hughes]

That worked a treat. Thanks a lot.