de-bug problem

[Lassie]

i'm tying to establish that my function is returning the right values, but my de bug line fails to print.
Can anyone help please?
code is
function display_dl_link($cart,$product_id)
{

// query database for all details for a particular book

  if (!$product_id || $product_id=='')
    return false;
$connection = db_connect();   
  $query = "select dl_link from products where product_id='$product_id'";
  $result = mysql_query($query);
  if (!$result)
    return false;
   
  while ($row = mysql_fetch_assoc($result)){

echo $row['dl_link'];//print to establish record pulled from db

}
}
Thanks,
lassie.

[Psycho]

There are two things to checl. 1) Is your query causing an error and 2) is it returning any results.

Try this:
[code]<?php
function display_dl_link($cart,$product_id) {

// query database for all details for a particular book

  if (!$product_id || $product_id=='') {
      return false;
  }
  $connection = db_connect();   
  $query = "select dl_link from products where product_id='$product_id'";
  $result = mysql_query($query);
  if (!$result) {
      mysql_error();
      return false;
  }

  if (mysql_num_rows($result)==0) {
      echo "There were 0 results";
  } else {
      while ($row = mysql_fetch_assoc($result)){
        echo $row['dl_link'];//print to establish record pulled from db
      }
  }
}

?>[/code]

[Lassie]

Thanks for that it worked just fine.
lassie