通过php在mysql中检查值的代码，成功返回将重定向到另一页。基本上，我想在字段中输入的代码将在MySQL表中检查，如果找到，则检查下一列的状态，如果未使用，则使它使用，用户将重定向到注册页面。根据建议进行更改，在网页上收到错误。
redeem-code.php：
<?php
error_reporting(E_ALL);
ini_set('display_errors', 1);
?>
<html>
<head>
<?php
$servername = "localhost";
$username = "root";
$password = "root";
$dbname = "redeem_code";
$rcode = "";
$status = "";
$errors = array();
$db = mysqli_connect($servername, $username, $password, $dbname);
// call the redeem() function if redeem_btn is clicked
if (isset($_POST['redeem_btn'])) {
$err = array();
redeem();
}
// Redeem Code
function redeem(){
// call these variables with the global keyword to make them available in function
global $db, $errors, $rcode, $status;
// receive all input values from the form. Call the e() function
// defined below to escape form values
$rcode = e($_POST['rcode']);
$status = e($_POST['status']);
// form validation: ensure that the form is correctly filled
if (empty($rcode)) {
array_push($errors, "Code is required");
}
// Redeem Code if there are no errors in the form
if (count($errors) == 1) {
$query = "SELECT * FROM redeem_codes WHERE rcode='$rcode' LIMIT 1";
$results = mysqli_query($db, $query);
if (mysqli_num_rows($results) == 0) {
$code_found = mysqli_fetch_assoc($results);
if ($code_found['status'] == 'unused') {
header('location: register.php');
}else{
echo "Code not found";
header('location: index.php');
}
}
else {
echo "error";
//array_push($errors, "Invalid Code");
}
}
}
?>
</head>
<body>
<?php foreach( $err as $line ) { ?>
<div style="error"><?php echo $line; ?></div>
<?php } ?>
<div class="widget">
<h3>Redeem Code</h3>
<form method="post" action="redeem.php" role="form" class="contactForm text-left">
<div class="form-group">
<input type="text" name="rcode" class="form-control" id="rcode" placeholder="Enter code" data-rule="minlen:4" data-msg="Please enter at least 4 chars" />
<div class="validation"></div>
</div>
<div class="text-left"><button type="submit" class="btn btn-primary btn-lg" name="redeem_btn">Redeem</button>
</div>
</form>
</div>
</body>
</html>