PHP历程（PHP与MYSQL数据库之间连接、创建和关闭）

<?php
define('WXLEVELS_DB_HOST','127.0.0.1');    //服务器
define('WXLEVELS_DB_USER','root');         //数据库用户名
define('WXLEVELS_DB_PASS','123456');       //数据库密码
define('WXLEVELS_DB_NAME','PvUv');   //默认数据库
define('DB_CHARSET','utf8');               //数据库字符集
define('TIMEZONE',"PRC");                  //时区设置

class dataConn{

    public function dataConn($host=WXLEVELS_DB_HOST ,$username=WXLEVELS_DB_USER,$password=WXLEVELS_DB_PASS,$dbname=WXLEVELS_DB_NAME)
    {
        $this->host = $host;
        $this->username = $username;
        $this->password = $password;
        $this->dbname = $dbname;

    }

    public function open()
    {
        $this->conn = mysql_connect($this->host,$this->username,$this->password) or die ('数据库连接失败！</br>错误原因：'.mysql_error());
        mysql_select_db($this->dbname) or die('数据库选定失败！</br>错误原因：'.mysql_error());
        mysql_query("SET CHARACTER SET utf8");
    }

    public function close()
    {
        mysql_close($this->conn);
    }

}