Shopping Cart - Not Working

[Dysan]

On executing the code below, an error message appears. Why is this?

 

Warning: mysql_fetch_array(): supplied argument is not a valid MySQL result resource in C:\Documents and Settings\User\Desktop\Xampp\htdocs\cart.php on line 51

 

$total = 0;
echo '<table>';
foreach ($contents as $id=>$qty) {
$sql = 'SELECT * FROM books WHERE id = '.$id;
$result = mysql_query($sql);

$row = mysql_fetch_array($result);

echo '<tr>';
echo '<td><a href="cart.php?action=delete&id='.$id.'" class="r">Remove</a></td>';
echo '<td>'.$row['title'].' by '.$author.'</td>';
echo '<td>£'.$price.'</td>';
echo '<td><input type="text" name="qty'.$id.'" value="'.$qty.'" size="3" maxlength="3" /></td>';
echo '<td>£'.($price * $qty).'</td>';
$total += $price * $qty;
echo '</tr>';
}
echo '</table>';
echo '<p>Grand total: £'.$total.'</p>';

echo writeShoppingCart();
echo '<a href="cart.php?action=add&id=1">Add to cart</a>';

[alecks]

print $result and see what it comes out with, it is probably returning (I think your query is incorrectly formatted)

 

$sql = "SELECT * FROM `books` WHERE `id` = '$id'";
$result = mysql_query($sql);

[Dysan]

Can data in the database be displayed without using a while loop. Obviously only one record will get displayed.

 

mysql_select_db("db", $con);

$result = mysql_query("SELECT * FROM details");

while($row = mysql_fetch_array($result))
{
  echo $row['FirstName'] . " " . $row['LastName'];
  echo "<br />";
}