MySQL更新数据库错误

Question

我试图获取它，以便当您按下按钮时它会将“订阅”的值更新为 1，但由于某种原因它不起作用。

<?php
session_start();
$userid = $_SESSION['userID'];
$username = $_SESSION['username'];
require '../../core/connect.php';

if ($_SESSION['userID']) {
    if (isset($_POST['subscribe'])) {

        $query2 = mysql_query("UPDATE `users` SET `subscribe`='1' WHERE `username`='".$username."'") or die(mysql_error());

        if ($query2) {
            header("Location: /index.php");
        } else {
            echo "An error occured. Your subscription failed! Please try again later.";
        }
    }else {
        echo "Error occured.";
    }
}else {
    echo "No session found.";
}
?>

我收到的错误是“发生错误”。

该字段为int，默认值为0

谢谢!

Answer 1

“发生错误”意味着

if(isset($_POST['subscribe'])) // is evaluating to false

使用

print_r($_POST) // and post the result