$cursor = $collection->find();
   <?php while ($cursor->hasNext()):
$article = $cursor->getNext(); ?>
<h2><?php echo $article['title']; ?></h2>
  ............

  找某条记录：$article = $collection->findOne(array('_id'=>
new MongoId($id)));
    查找时也可以传入多个参数：
$moviesCollection->find(array('genre' => 'comedy', 'year' => 2011));
   if ($cursor->count() === 0)  //如果找不到
 
   如果查询多个条件：
   $collection->find(array('x' => array('$gt' => 100)));
//$ is escaped within double quotes (")
$collection->find(array('x' => array("\$gt" => 100)));
   注意要用单引号，如果要用双引号，则要加上转义符。