php - 警告：mysqli_num_rows() 需要参数 1

Question

// LOGIN USER
if (isset($_POST['login_user'])) {
    $username = ($_POST['username']);
    $password = ($_POST['password']);

    if (empty($username)) {
        array_push($errors, "Username is required");
    }
    if (empty($password)) {
        array_push($errors, "Password is required");
    }

    if (count($errors) == 0) {
        $password = md5($password);
        $query = "SELECT * FROM users WHERE username='$username' AND password='$password'";
        $results =( $query);

        if (mysqli_num_rows($results) == 1) {
            $_SESSION['username'] = $username;
            $_SESSION['success'] = "You are now logged in";
            header('location: index.php');
    }else {
            array_push($errors, "Wrong username/password combination");
        }
    }
} 

警告：mysqli_num_rows() 期望参数 1 为 mysqli_result，字符串在第 63 行的 C:\xampp\htdocs\test4\server.php 中给出

标签： phpmysqlmysqli

Answer 1

mysqli_num_rows期望一个mysqli_result.

代替

$results = ($query);

和

$results = mysqli_query($query);