class MySQLDB{
private $host;
private $port;
private $username;
private $password;
private $charset;
private $dbname;
private $source;//储存链接后的资源
private static $instance;
private function __construct($config){
//初始化6项数据
$this->connect();//链接数据库
$this->setcharset($this->charset);//设定编码
$this->selectdb($this->dbname);//选定数据库
}
private function __clone(){}
static function getInstance($config){
if(!isset(self::$instance)){
self::$instance = new self($config);
}
return self::$instance;
}
private function connect(){}
function setcharset($charset){
//设定编码
}
function selectdb($db){
//设定数据库
}
function query($sql){
//执行所有sql语句
}
function fetchAll($sql){
// 取得多行数据返回二维数组
}
function fetchAll($sql){
// 取得一行数据返回二维数组
}
function fetchAll($sql){
// 取得1行1列数据返回二维数组
}
}