php用mysqli模块连数据库Fatal error: Call to a member function query() 。解决思路

php用mysqli模块连数据库Fatal error: Call to a member function query() 。。。。
出现了这个错误：Fatal error: Call to a member function query() on a non-object in D:\wamp\www\bills\model\UserDB.class.php on line 24
代码如下：

PHP code

mysqli=new mysqli($dbhost,$dbuser,$dbpwd,$dbname); if(mysqli_connect_errno()) { echo "物品数据库连接失败！"; } } public function close() { if($this->mysqli) $this->mysqli->close(); $this->mysqli=FALSE; } public function _destruct() { $this->close(); } } class UserDB extends Database { public function queryUserByName($name) { $query="SELECT * FROM Users WHERE name='".$name."'"; if ($result=$this->mysqli->query($query)) //此处提示出错！！ return true; else return false; }

登入後複製

然后在另一个页面里调用上面的类对象：

PHP code

queryUserByName($lvalue["name"]); echo "alert"; if($rtmp) //这个名字没有注册 { $rusers=new User($lvalue); if($udb->addUser($rusers)) { setcookie("start",0); setcookie("userInfo",serialize($rusers)); setcookie("username",$rusers->name); header("Location:../view/index.php"); } else header("Location:../view/errors.php?value=tianjia"); } break; }

登入後複製

------解决方案--------------------
public function __construct($configFile="config.inc.php") //两个下划线