很好的一天！我得到一个错误，上面写着“未定义的变量：id”。
我创建了一个表，每一行都有一个delete按钮，单击它会弹出一个模式，询问是否要删除该行。但是当我点击delete按钮时，它会显示error undefined variable:id，并且不会删除数据。
这是我的表格代码：

if(isset($_POST['delete'])) {
        $data->delete_multiple($id, $conn);

    }

    <table class="table table-hover table-bordered" id="table1">
                                    <thead>
                                        <tr>
                                            <th>Faculty Code</th>
                                            <th>Last Name</th>
                                            <th>First Name</th>
                                            <th>Middle Name</th>
                                            <th>Position</th>
                                            <th></th>
                                            <th>Status</th>
                                        </tr>
                                    </thead>
                                    <tbody>
                                        <?php  while ($row = $result -> fetch_object()): ?>
                                        <tr>
                                            <td><?php echo  $row->Faculty_ID;?></td>
                                            <td><?php echo $row->Faculty_Lastname ?></td>
                                            <td><?php echo $row->Faculty_Firstname ?></td>
                                            <td><?php echo $row->Faculty_Middlename?></td>
                                            <td><?php echo $row->Position; ?></td>
                                            <td class="text-center">
                                                <a  class="btn btn-sm btn-outline-primary text-muted" href="Faculty_edit.php?Faculty_ID=<?php echo $row->Faculty_ID;?>">Edit</a>
                                                <a type="button"  title="Delete Faculty" data-toggle="modal" data-target="#delete_modal"  class="btn btn-sm btn-outline-danger" >Delete</button></td>
                                            <td>
                                                <?php if($row->Status=='Active') echo '<a href="#deactive_account" data-toggle="modal" data-id='.$row->Faculty_ID.' class="activate" style="color:green;">Active</a>'; ?>
                                                <?php if($row->Status=='Inactive') echo '<a href="#active_modal" data-toggle="modal" data-id='.$row->Faculty_ID.' class="activate" style="color:red;">Inactive</a>'; ?>
                                            </td>
                                        </tr>
                                        <?php endwhile; ?>
                                    </tbody>
                                </table>

我的模式代码：

<div class="modal fade" id="delete_modal" role="dialog">
                      <div class="modal-dialog">
                        <div class="modal-content">
                          <!-- Modal Header -->
                          <div class="modal-header">
                            <h4 class="modal-title">Delete Confirmaiton</h4>
                            <button type="button" class="close" data-dismiss="modal">&times;</button>
                          </div>
                          <!-- Modal body -->
                          <div class="modal-body">
                            <div class="alert alert-danger" role="alert">
                              Are you sure you want to delete selected record?
                            </div>
                          </div>
                          <!-- Modal footer -->
                          <div class="modal-footer">
                            <button type="button" class="btn btn-default" data-dismiss="modal">No</button>
                            <button type="submit" class="btn btn-danger" name="delete">Yes</button>
                          </div>
                        </div>
                      </div>
                    </div>

删除功能代码：

function delete_multiple($id, $conn){

         $id = $_POST['delete'];
         $sql = "DELETE FROM faculty WHERE Faculty_ID=? ";
            $stmt = $conn->prepare($sql);
            $stmt->bind_param("i", $id);
            $stmt->execute();    
        }