mysql_fetch_array() Warning

[nomad]

I having troubles with this code I'm getting a error code.
Please not this is not an assignment its from a book called PHP Bible. This book is loaded with errors.

Warning: mysql_fetch_arr ay() expects parameter 1 to be resource, boolean given in /Applications/XAMPP/xamppfiles/htdocs/testing/10/ch21/date_prefs.php on line 33 (note line 33 is in bold text)
or
$pref_arr = mysql_fetch_arr ay($result); note I'm also get errors on other examples in this book.

<?php

// Subscriber ID is stored in a cookie on the user's browser
$sub_id = $_COOKIE['userID'];

// Open connection to the database
mysql_connect("localhost", "nomad", "nomad") or die("Failure to communicate with database");
mysql_select_db("test");

// If the form has been submitted, record the preferences
if ($_POST['submit'] == 'Submit') {
  $height = $_POST['height'];
  $haircolor = $_POST['haircolor'];
  $edu = $_POST['edu'];

  // Update value
  $query = "UPDATE qualities
            SET height = $height, haircolor = $haircolor, edu = $edu
            WHERE subscriber = $sub_id";
  $result = mysql_query($query);
  if (mysql_affected_rows() == 1) {
    $success_msg = '<P>Your preferences have been updated.</P>';
  } else {
    error_log(mysql_error());
    $success_msg = '<P>Something went wrong.</P>';
  }

}

// Get the values
$query = "SELECT height, haircolor, edu FROM qualities WHERE subscriber = $sub_id";
$result = mysql_query($query);
[B]$pref_arr = mysql_fetch_array($result);[/B]   
$height = $pref_arr[0];
$haircolor = $pref_arr[1];
$edu = $pref_arr[2];

// Assemble the radio button part of the form
...more code below

?>

If you need the db and table information please let me know.

Any help would be great.

nomad

[code green]

The error message means mysql_query() returned FALSE,
which means an error occurred.
Try the query on its own

[Dormilich]

or try mysql_error().