我对php和mysql很陌生。我在索引中添加了一个注册字段“referror”。我添加它最简单的方法就是在player表中添加ref行。当用户在注册期间输入一个引用时，它会被存储到数据库中，而不检查新用户输入的用户名是否有效。

if (isset($_POST['register'])) {
    $username = $_POST['username'];
    $password = hash('sha256', $_POST['password']);
    $email    = $_POST['email'];
    $ref      = $_POST['ref'];
    $sql = mysqli_query($connect, "SELECT username FROM `players` WHERE username='$username'");
    if (mysqli_num_rows($sql) > 0) {
        echo '<br /><div class="alert alert-danger"><i class="fa fa-exclamation-circle"></i> ' . lang_key("username_taken") . '</div>';
    } else {
        $sql2 = mysqli_query($connect, "SELECT email FROM `players` WHERE email='$email'");
        if (mysqli_num_rows($sql2) > 0) {
            echo '<br /><div class="alert alert-danger"><i class="fa fa-exclamation-circle"></i>  ' . lang_key("email_taken") . '</div>';
        } else {
            $money    = $row['startmoney'];
            $gold     = $row['startgold'];
            $themeid  = $rowtd['id'];
            $langcode = $rowld['langcode'];

            $insert = mysqli_query($connect, "INSERT INTO `players` (username, password, email, ref, money, gold, theme, language) VALUES ('$username', '$password', '$email', '$ref', '$money', '$gold', '$themeid', '$langcode')");

今天，我希望在推荐人时给予奖励。所以我一直在分解我要做的事情。我想出了这样的办法。

$sql3 = mysqli_query($connect, "SELECT ref FROM `players` WHERE ref='$ref'");
    if (mysqli_num_rows($sql3) > 0) {
        echo $player_update = mysqli_query($connect, "UPDATE `players` SET money=money+'5000' WHERE ref='$ref'");';
   }else{

这不起作用，我不确定这是否是我应该做的第一位。。我是一个初学者，自学成才，所以小费将非常感谢，谢谢大家阅读/帮助！