Question

我从androidhive下载了这段代码。它是Android应用程序的登录/注册代码。现在php代码来自两年前，所以我最初得到了折旧错误，所以我开始将代码更新到mysqli.So远在转换时，我已经将mysql函数更改为mysqli，如果需要调整参数。我一般都对php很新，所以我遇到了一些问题，主要的问题是DB_functions中isUserExisted函数的问题，mysqli_query的变量db是未定义的。我不确定为什么我会收到此错误，因为我已在构造函数中定义了它。我已经查看了类似的问题，修复问题的答案通常是语法错误，当我比较这些代码时，我似乎没有。任何帮助将不胜感激。这里分别是DB_Functions.php和DB_Connect.php：

＆＃13;

<?php

class DB_Functions {

	private $db = null;

    //put your code here
    // constructor
    function __construct() {
        require 'DB_Connect.php';
		
        // connecting to database
        $this->db = new DB_Connect();
        $this->db->connectThis();
		
    }

    // destructor
    function __destruct() {
        
    }

    /**
     * Storing new user
     * returns user details
     */
    public function storeUser($name, $email, $password) {
        $uuid = uniqid('', true);
        $hash = $this->hashSSHA($password);
        $encrypted_password = $hash["encrypted"]; // encrypted password
        $salt = $hash["salt"]; // salt
        $result = mysqli_query($db,"INSERT INTO users(unique_id, name, email, encrypted_password, salt, created_at) VALUES('$uuid', '$name', '$email', '$encrypted_password', '$salt', NOW())");
        // check for successful store
        if ($result) {
            // get user details 
            $uid = mysqli_insert_id(); // last inserted id
            $result = mysqli_query($db,"SELECT * FROM users WHERE uid = $uid");
            // return user details
            return mysqli_fetch_array($result);
        } else {
            return false;
        }
    }

    /**
     * Get user by email and password
     */
    public function getUserByEmailAndPassword($email, $password) {
        $result = mysqli_query($db,"SELECT * FROM users WHERE email = '$email'") or die(mysql_error());
        // check for result 
        $no_of_rows = mysqli_num_rows($result);
        if ($no_of_rows > 0) {
            $result = mysqli_fetch_array($result);
            $salt = $result['salt'];
            $encrypted_password = $result['encrypted_password'];
            $hash = $this->checkhashSSHA($salt, $password);
            // check for password equality
            if ($encrypted_password == $hash) {
                // user authentication details are correct
                return $result;
            }
        } else {
            // user not found
            return false;
        }
    }

    /**
     * Check user is existed or not
     */
    public function isUserExisted($email) {
        $result = mysqli_query($db,"SELECT email from users WHERE email = '$email'");
        $no_of_rows = mysqli_num_rows($result);
        if ($no_of_rows > 0) {
            // user existed 
            return true;
        } else {
            // user not existed
            return false;
        }
    }

    /**
     * Encrypting password
     * @param password
     * returns salt and encrypted password
     */
    public function hashSSHA($password) {

        $salt = sha1(rand());
        $salt = substr($salt, 0, 10);
        $encrypted = base64_encode(sha1($password . $salt, true) . $salt);
        $hash = array("salt" => $salt, "encrypted" => $encrypted);
        return $hash;
    }

    /**
     * Decrypting password
     * @param salt, password
     * returns hash string
     */
    public function checkhashSSHA($salt, $password) {

        $hash = base64_encode(sha1($password . $salt, true) . $salt);

        return $hash;
    }

}

?>

＆＃13;

<?php
class DB_Connect {
	

    // constructor
    function __construct() {
        
    }

    // destructor
    function __destruct() {
        // $this->close();
    }

    // Connecting to database
    public function connectThis() {
        require 'include/Config.php';
        // connecting to mysql
        $db = mysqli_connect(DB_HOST, DB_USER, DB_PASSWORD, DB_DATABASE) or die(mysqli_error());
		// selecting database

        // return database handler
        return $db;
    }

    // Closing database connection
    public function close() {
        mysqli_close();
    }

}

?>

＆＃13;

Answer 1

你需要这样称呼它：

$result = mysqli_query($this->db,"SELECT email from users WHERE email = '$email'");

Answer 2

我终于明白了！在使用了解决我原来问题的严肃的建议之后，我立即遇到了mysqli_query需要＆＃34; mysqli＆＃34;的错误，但却得到了一个对象。我通过对互联网的评分意识到这是因为我在DB_function.php的构造函数中声明了我的连接，因此它使它成为一个对象，从而产生错误。我不认为这是最好的方法，但是对于每个需要连接数据库的函数我写道：

$conn = mysqli_connect(DB_HOST, DB_USER, DB_PASSWORD, DB_DATABASE) or die(mysqli_error());

在DB_Functions.php的每个函数中，并将$ conn作为调用mysqli_query的第一个参数传递。代码现在完美无缺。

将php代码从mysql更新为mysqli，未定义的变量，但在构造函数中定义

2 个答案: