The Drupal Dynamic Query

drupaDynamicQuery.php

<?php
$query = db_select('users', 'u');

$query
  ->condition('u.uid', 0, '<>')
  ->fields('u', array('uid', 'name', 'status', 'created', 'access'))
  ->range(0, 50);

$result = $query->execute();

//The above is roughly equivalent to
$result = db_query("SELECT uid, name, status, created, access FROM {users} u WHERE uid <> 0 LIMIT 50 OFFSET 0");

?>