admin无效的用户名和密码错误

Question

sql连接的代码：

<?php 
define('DB_SERVER','localhost');
define('DB_USER','root');
define('DB_PASS' ,'');
define('DB_NAME', 'shopping');
$con = mysqli_connect(DB_SERVER,DB_USER,DB_PASS,DB_NAME);
// Check connection
if (mysqli_connect_errno())
{
    echo "Failed to connect to MySQL: " . mysqli_connect_error();
}
?>

登录代码：

<?php
session_start();
error_reporting(0);
include("include/config.php");
if(isset($_POST['submit']))
{
    $username=$_POST['username'];
    $password=md5($_POST['password']);
    $ret=mysqli_query($con,"SELECT * FROM admin WHERE username='$username' and password='$password'");
    $num=mysqli_fetch_array($ret);
    if($num>0)
    {
        $extra="change-password.php";//
        $_SESSION['alogin']=$_POST['username'];
        $_SESSION['id']=$num['id'];
        $host=$_SERVER['HTTP_HOST'];
        $uri=rtrim(dirname($_SERVER['PHP_SELF']),'/\\');
        header("location:http://$host$uri/$extra");
        exit();
    }
    else
    {
        $_SESSION['errmsg']="Invalid username or password";
        $extra="index.php";
        $host = $_SERVER['HTTP_HOST'];
        $uri = rtrim(dirname($_SERVER['PHP_SELF']),'/\\');
        header("location:http://$host$uri/$extra");
        exit();
    }
 }
 ?>

即使用户名和密码正确，它也会一直提供无效的用户名和密码错误。与mysql服务器连接完成并正常工作但在管理员惩罚中以admin身份登录。

Answer 1

mysqli_fetch_array返回一个数组，而不是数字。请改用count($num) > 0