/**
* 构造查询
*
* @param Mongo $mongo MongoDB连接
* @param string $db 数据库
* @param string $collection 集合
*/
function __construct(RMongo $mongo, $db, $collection)
{
$this->_dbName = $db;
$this->_collectionName = $collection;
$this->_db = $mongo->selectDB($this->_dbName);
$this->_collection = $mongo->selectCollection($this->_dbName, $this->_collectionName);
}
