A database abstraction layer is bundled with PHP 4. In the example below, the only thing you would need to change to use a different database is the odbc word on the third line.

<?php
  require_once 'DB.php';
  $db = DB::connect('odbc://user:pw@host/mydb');
  $stmt = $db->prepare('SELECT * FROM comments');
  $result = $db->execute($stmt);
  while($row = $db->fetchrow($result)) {
     while($row as $field => $value ) {
        echo "$field: $value<br>\n";
     }
  }
  $db->disconnect();
?>