完善ecshop的mysql类

<?php
header("Content-Type:text/html;charset=utf-8");
date_default_timezone_set("Etc/GMT-8");
error_reporting(E_ALL ^ E_NOTICE);
global $db;
define('IN_ECS', true);
define('EC_CHARSET', 'utf-8');
define('ROOT_PATH', dirname(__FILE__).'\..\\');
define('DATA_DIR', 'data');
$db_host = "localhost:3306";
$db_name = "duizhang";
$db_user = "root";
$db_pass = "";
$prefix = "mydb_";
require(ROOT_PATH.'Classes/cls_mysql.php');
$db = new cls_mysql($db_host, $db_user, $db_pass, $db_name, $prefix);
?>

var $db_name = '';
var $prefix = '';

function __construct($dbhost, $dbuser, $dbpw, $dbname = '', $prefix = '', $charset = 'gbk', $pconnect = 0, $quiet = 0)
{
$this->db_name = $dbname;
$this->prefix = $prefix;
$this->cls_mysql($dbhost, $dbuser, $dbpw, $dbname, $prefix, $charset, $pconnect, $quiet);
}

function cls_mysql($dbhost, $dbuser, $dbpw, $dbname = '', $prefix = '', $charset = 'gbk', $pconnect = 0, $quiet = 0)

'prefix' => $prefix,

function table($str)
{
return '`' . $this->db_name . '`.`' . $this->prefix . $str . '`';
}

$sql = 'SELECT * FROM '.$db->table('member').' WHERE 1';
echo $sql;exit;