public function __construct($config = '')
{
if (!extension_loaded('mysql')) {
//E(L('_NOT_SUPPERT_').':mysql');
throw new Exception("_NOT_SUPPERT_:mysql");
}
if (!empty($config)) {
$this->config = $config;
if (empty($this->config['params'])) {
$this->config['params'] = '';
}
}
}