PDO封装

<?php
class PDOA
{
    public $host = "localhost";
    public $uid = "root";
    public $pwd = "";

    //执行SQL语句的方法，$type代表SQL语句的类型，0代表查询
    public function Prepare($sql,$typepdo = 0,$db = "mydb",$fwq = "mysql")
    {
        $dsn = "$fwq:dbname=$db;host=$this->host";
        $pdo = new PDO($dsn,$this->uid,$this->pwd);
        $stm = $pdo->prepare($sql);
        if($stm->execute())
        {
            if($typepdo == 0)
            {
                return $stm->fetchAll(PDO::FETCH_ASSOC);
            }
            else
            {
                echo "执行成功";
                return $stm->execute();
            }
        }
        else
        {
            echo "执行失败";
        }
    }

    }