php - 致命错误：未捕获的错误：在 null 上调用成员函数 dbConnect()

Question

请帮帮我..我的代码有什么问题。我尝试创建登录表单并验证输入..

致命错误：未捕获的错误：在 null 上调用成员函数 dbConnect()

（开 $this->$db = $this->db->dbConnect();）。

这是connection.php

<?php

class connection{

    public $db_host = 'localhost';
    public $db_name = 'login';
    public $db_user = 'root';
    public $db_pass = 'root';

    public function dbConnect()
    {
        try{
            $conn = new PDO("mysql:host=".$this->db_host.";dbname=".$this->db_name,$this->db_user,$this->db_pass);
           $conn->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
        }
        catch(PDOException $e)
        {
            echo 'ERROR: ' . $e->getMessage();
        }    
        return $this->conn;
    }
}

?>

这是 login.php

<?php

include_once('connection.php');

class User{

    private $db;
    public function __construct(){

        $this->$db = new connection();
        $this->$db = $this->db->dbConnect();

    }

    public function isAuthenticated($name, $pass){

        if(!empty($name) && !empty($pass)){

            $st = $this->$db->prepare("SELECT * FROM loginUser WHERE username =? AND password =?");
            $st->bindParam(1, $name);
            $st->bindParam(2, $pass);
            $st->execute();

            if($st->rowCount() == 1){
                echo "User Verified";
            }else{
                echo "Incorrect UserName or Password";
            }

        }else{

            echo "Please Enter User Name And Password";
        }

    }



}

?>

标签： phppdo

Answer 1

替换这个：

    $this->$db = new connection();
    $this->$db = $this->db->dbConnect();

有了这个：

    $this->db = (new connection())->dbConnect();

和这个：

$this->$db->prepare

有了这个：

$this->db->prepare

实际上，在每个地方你都应该更换：

$this->$db

和

$this->db