function not returning query

[Allen McCabe <allenmccabe@xxxxxxxxx>]

Hi, thanks for reading, I hope you can help:

In my main file for an orders page I have the following code:


if (isset($_GET['filterby']))
 {
  $resultOrders = adminFilterQuery();
  $numberOfOrders = mysql_num_rows($resultOrders);
 }
 else
 {
  $resultOrders = mysql_query("SELECT * FROM afy_order;") or
die(mysql_error("Could not query the database!"));
  $numberOfOrders = mysql_num_rows($resultOrders);
 }


adminFilterQuery() is a custom function that is supposed to return a
mysql_query, here are the last few lines of this function:


$query = "SELECT * FROM afy_order WHERE school_id = '{$school}' ORDER BY
{$order_by_param};";
$result = mysql_query($query);
return $result;

l am getting this error when I try to filter my query using a form in tandem
with the quey building function:

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

where the line is the one where I use the mysql_num_rows function.

What am I missing here?

Thanks!