<?php
class DB{
const HOST='127.0.0.1';
const USER='root';
const PASS='root';
const DATA='mooc';
static public $_instance;
private function __construct(){
mysql_connect(DB::HOST,DB::USER,DB::PASS);
mysql_set_charset('utf8');
mysql_select_db(DB::DATA);
}
public static function getInstance(){
if(!self::$_instance instanceof self){
self::$_instance=new self;
}
return self::$_instance;
}
}
$model=DB::getInstance();
//连接数据库,并且测试
$sql="select * from user";
$res=mysql_query($sql);
while($row=mysql_fetch_assoc($res)){
var_dump($row);
}
?>