php mysql query throwing errors

Question

what is wrong with this script? it keeps giving my erros but will not tell me what is wrong

I need this to lookup channel number from the item number passed in url. then echo the channel number

<?php
$id = $_GET['item'];
if (!$link = mysql_connect('server', 'user', 'pass')) {
    echo 'Could not connect to mysql';
    exit;
}

if (!mysql_select_db('xmlrpc', $link)) {
    echo 'Could not select database';
    exit;
}

 $sql = mysql_query("SELECT channel FROM channels WHERE item = '".$_GET['item']."'")or die(mysql_error());
$result = mysql_query($sql, $link);

if (!$result) {
    echo "DB Error, could not query the database\n";
    echo 'MySQL Error: ' . mysql_error();
    exit;
}

while ($row = mysql_fetch_assoc($result)) {
    echo $row['channel'];
}

mysql_free_result($result);

?>

Answer 1

 $sql = mysql_query("SELECT channel FROM channels WHERE item = '".$_GET['item']."'") or die(mysql_error());

To

 $sql = "SELECT channel FROM channels WHERE item = '".$_GET['item']."'";

As a sidenote do not use mysql_ functions, they became obsolete (PHP 5.5). Use PDO instead for example, as it stands your code is vulnerable to SQL injections.

Answer 2

when item is already declared as a variable $id

$id = $_GET['item'];

you could already use it as a variable in your mysql

$sql = mysql_query("SELECT channel FROM channels WHERE item = '".$_GET['item']."'")or die(mysql_error());

change it into

$sql="SELECT * FROM channels WHERE item ='$id'";