二手回收网站利用PHP开发的在线退货申请功能

<?php
//连接到数据库
$mysqli = new mysqli("localhost", "username", "password", "database");

//检查数据库连接是否成功
if ($mysqli->connect_errno) {
  die("数据库连接失败：" . $mysqli->connect_error);
}

//处理退货申请
if ($_SERVER["REQUEST_METHOD"] == "POST") {
  $order_id = $_POST["order_id"];
  $reason = $_POST["reason"];
  $description = $_POST["description"];
  
  //将退货记录插入数据库
  $query = "INSERT INTO returns (order_id, reason, description, status, created_at) VALUES ('$order_id', '$reason', '$description', '待审核', NOW())";
  
  if ($result = $mysqli->query($query)) {
    //退货申请成功
    echo "退货申请已提交";
  } else {
    //退货申请失败
    echo "提交退货申请失败：" . $mysqli->error;
  }
}

//关闭数据库连接
$mysqli->close();
?>

<form action="return.php" method="POST">
  <label for="order_id">订单号：</label>
  <input type="text" name="order_id" required><br>
  
  <label for="reason">退货原因：</label>
  <select name="reason" required>
    <option value="">请选择退货原因</option>
    <option value="质量问题">质量问题</option>
    <option value="不喜欢">不喜欢</option>
    <option value="尺寸不合适">尺寸不合适</option>
    <!-- 其他退货原因选项 -->
  </select><br>
  
  <label for="description">退货说明：</label>
  <textarea name="description"></textarea><br>
  
  <input type="submit" value="提交退货申请">
</form>