php - 注册或登录表 fatal error

Question

以下PHP / MySQL代码无法正常工作，并在连接到MySQL表时产生致命错误，我正在尝试制作一个注册表和登录表（在同一页面上，使用不同的z-indexs和hide and show button ，但由于某些MySQL致命错误而无法加载，我正尽力将其完成，但看来我的教程已经过时，或者试图以完全无效的方式将其复制到我的情况下。

if (session_status() == PHP_SESSION_NONE) {
    session_start();
}
$mysql = mysql_connect("localhost:****", "*****", "W*********") or die("Failed to connect to MySQL: " . mysql_error());
$db=mysql_select_db('matrixhu_logins',$mysql) or die("Failed to connect to MySQL: " . mysql_error());
if(isset($_POST['log'])) {
$username = $_POST['usr'];
$password = $_POST['pass'];
$query = "SELECT * FROM users WHERE username = '$username' AND password = '$password'";
$data = mysql_query($query) or die("Failed to connect to MySQL: " . mysql_error());
if($data) {
    echo "It Worked!"
} else if(isset($_POST['sign'])) {
    $username = $_POST['username'];
    $password = $_POST['password'];
    $passconfirm = $_POST['confirmpass'];
    $email = $_POST['email'];
    $bio = $_POST['bio'];
    if($password !== $passconfirm) {
        $error = "Passwords are not the same!";
        die;
    }
    $query = "INSERT INTO users (username,password,email,bio) VALUES ('$username','$password','$email','$bio')";
    $data = mysqli_query($query) or die("Failed to connect to MySQL: " . mysqli_error());
    if($data) {
        echo "Success!";
    }
} else {
    $username = "Guest";
}

Answer 1

到处都使用mysqli而不是mysql。问题是您在某些地方使用mysqli，而在某些地方使用mysqli。另外，您还要混合两者的语法。

if (session_status() == PHP_SESSION_NONE) {
    session_start();
}
$mysql = mysqli_connect("localhost:****", "*****", "W*********") or die("Failed to connect to MySQL: " . mysqli_error());
$db=mysqli_select_db($mysql,'matrixhu_logins') or die("Failed to connect to MySQL: " . mysql_error());
if(isset($_POST['log'])) {
$username = $_POST['usr'];
$password = $_POST['pass'];
$query = "SELECT * FROM users WHERE username = '$username' AND password = '$password'";
$data = mysqli_query($mysql,$query) or die("Failed to connect to MySQL: " . mysqli_error());
if($data) {
    echo "It Worked!"
} else if(isset($_POST['sign'])) {
    $username = $_POST['username'];
    $password = $_POST['password'];
    $passconfirm = $_POST['confirmpass'];
    $email = $_POST['email'];
    $bio = $_POST['bio'];
    if($password !== $passconfirm) {
        $error = "Passwords are not the same!";
        die;
    }
    $query = "INSERT INTO users (username,password,email,bio) VALUES ('$username','$password','$email','$bio')";
    $data = mysqli_query($mysql,$query) or die("Failed to connect to MySQL: " . mysqli_error());
    if($data) {
        echo "Success!";
    }
} else {
    $username = "Guest";
}