Question

questions from a Newbie 🙂

I am trying to convert my MySQL query syntax into PDO but having some issues getting started.

I have an included file in my page called dbc.php. contains the code:

define ("DB_HOST", "localhost"); // set database host
define ("DB_USER", "dbuser"); // set database user
define ("DB_PASS","dbpass"); // set database password
define ("DB_NAME","dbname"); // set database name

$link = mysql_connect(DB_HOST, DB_USER, DB_PASS) or die("Couldn't make connection.");
$db = mysql_select_db(DB_NAME, $link) or die("Couldn't select database");

My Page code is then:

<?php
include 'dbc.php';
page_protect();

function get_users($db) {   
$getusers = $db->query('SELECT employeeid, fullname FROM Persons order by fullname asc');
}

?>

I want to display the table output with the following code:

<table>
    <tr>
        <th> Full Name</th>
    </tr>
    <?                      
        while($row = $getusers->fetch(PDO::FETCH_ASSOC)) 
        {
    ?>
    <tr>
        <td>
        <?
        echo $row['fullname'];
        ?>
        </td>
    </tr>
        <?
        }
        ?>
</table>

This currently outputs the error:

Fatal error: Call to a member function fetch() on a non-object in /home/she/public_html/versionfour/people.php on line 170

where line 170 is my ‘ while($row = $getusers->fetch(PDO::FETCH_ASSOC)) ‘ statement.

I know I am missing something simple here, probably for not completely understanding PDO as yet.

any help is apprecaited.

Thanks and regards,
R

Answer 1

This issue you have relates to the scope of the “$getUsers” variable. Because the function does not return its value the HTML file cannot access this and the fetch() method is trying to be called on a undefined value, hence the “non-object” part within the error.

<?php
  /** Include the db file which should define a connection as so
  $db = new PDO('dblib:host=$hostname;dbname=$dbName', $user, $pass); etc
  **/
  include 'dbc.php';

  page_protect();

  function get_users($db) 
  {   
    $result = $db->query("SELECT employeeid, fullname FROM Persons order by fullname asc");
    return $result;
  }
  $users = get_users($db);

  /** $users->fetch() can now be used **/

?>

You should also consider some error checking to ensure that the returned db result is actually a PDO result or you may still encounter this issue.