php - 按钮单击将用户重定向到另一个页面并发布

Question

当点击返回按钮时，我需要它重定向到fine_payment.php 页面。我试过 header() 但它显示：无法修改标头信息 - 标头已发送..

<form action="fine_payment.php" method="post">
     <button type="submit" name="return" id="submit" class="btn btn-info">Return Book </button>
     <input type="hidden" name="return_id" value="<?php echo $row['rid']; ?>"> 
</form>

同时，我需要运行这个 POST 代码：

if(isset($_POST['return'])){
    $id = $_POST['return_id'];
    $query = "SELECT * FROM issue_books WHERE id= $id ";
    $query_run = mysqli_query($connection,$query);

    while($row = mysqli_fetch_assoc($query_run))
    {
        $issue_date = strtotime($row['book_issue_date']);
        $due_date = strtotime($row['book_due_date']);
        $return_date = strtotime(date('Y-m-d'));

        $days_diff = $return_date - $due_date;
        if($days_diff >=0)
        {
            $_SESSION['day'] = floor($days_diff/(60*60*24));
        }
    }
}

标签： phpmysqlformssession