<?
class DbConn {
const DB_HOST = 'localhost';
const DB_USER = 'root';
const DB_PASS = 'pw';
const DB_NAME = 'db';
static private $instance = NULL;
private $_db;
static function getInstance()
{
if (self::$instance == NULL)
{
self::$instance = new DbConn();
if(mysqli_connect_errno()) {
throw new Exception("Database connection failed: ".mysqli_connect_error());
}
}
return self::$instance;
}
private function __construct()
{
$this->_db = new mysqli(self::DB_HOST, self::DB_USER, self::DB_PASS, self::DB_NAME) or die('Couldnt connect');
}
private function __clone() {}
}
DbConn::getInstance()->query();
?>
我只是学习,知道我得Singleton模式,我试着用单使自己的数据库连接类,但是当我试图执行它,它给调用DbConn时的错误: :的getInstance() - >查询();说调用未定义的方法DbConn :: query()我做错了什么?的mysqli和辛格尔顿
重要错误?它指向PHP或其他什么? – Diego