当我点击添加时，数据被保存并通过ajax显示在同一页面上但如果我想对数据进行排序，按钮不起作用

您可以修改每个函数以发送一个新参数 - 我选择了task但它并不重要。正如您将在 javascript 中看到的那样，每个请求类型的值都会更改。PHP 代码可以根据这个单一的 POST 变量查找然后派生逻辑。

仅供参考：盲目地提取 PHP 中的变量使用extract打开了各种攻击的大门 - 只有在清理 POST 数组后才谨慎使用它 - 可能filter_input_array用作可接受名称/类型的开始和白名单。

function addRecord(){
     var title = $('#title').val();
     var description = $('#description').val();

     $.ajax({
        url: "data.php",
        type: "POST",
        data: {
            task:'add',
            title:title,
            description:description
        },
        success: function(data, status)
        {
            readRecords();
        }
     });
}

function readRecords(){
    $.ajax({
        url: "data.php",
        type: "POST",
        data: {
            task:'read'
        },
        success: function(data, status)
        {
            $('#records').html(data);
        }
    });
}

function DeleteUser(deleteid){
    if( !confirm("you want to delete?") )return false;

    $.ajax({
        url: "data.php",
        type: "POST",
        data: {
            task:'delete',
            deleteid:deleteid
        },
        success: function(data, status)
        {
            readRecords();
        }
    });
    
}

function ascdRecord(e){
    $.ajax({
        url: "data.php",
        type: "POST",
        data:{
            task:'ascd'
        },
        dataType: "html",
        success: function(data)
        {
            $('#records').html(data);
        }
    });
}
/* presume similar for dscdRecord */
function descRecord(e){
    $.ajax({
        url: "data.php",
        type: "POST",
        data:{
            task:'dscd'
        },
        dataType: "html",
        success: function(data)
        {
            $('#records').html(data);
        }
    });
}

数据.php

if( isset( $_POST['task'] ) ){
    switch( $_POST['task'] ){
        case 'add':
            if(isset(
                $_POST['title'],
                $_POST['description']
            )){
                # this is prone to SQL injection - you should use a `Prepared statement`
                /*
                $insert_query = "insert into app.add () values('$title','$description')";
                $query_run = mysqli_query($con, $insert_query);
                */
                
                
                $sql='insert into `app`.`add` ( `title`, `description` ) values (?,?)';
                $stmt=$con->prepare($sql);
                $stmt->bind_param('ss',$_POST['title'],$_POST['description']);
                $stmt->execute();
                $stmt->close();
            }
            
        break;
        case 'delete':
        
        break;
        case 'read':
            
            $data = '
            <div class="result">
                <table>
                    <tr>
                        <th>Title</th>
                        <th>Description</th>
                    </tr>';

            $fetch_query = "select * from app.add";
            $fetch_run = mysqli_query($con, $fetch_query);

            if(mysqli_num_rows($fetch_run) > 0)
            {
                while($row = mysqli_fetch_array($fetch_run))
                {
                    $data .= '
                    <tr style="border: 1px solid black; padding: 8px; text-align: center">
                        <td style="border: 1px solid black; padding: 8px; text-align: center">'.$row['title'].'</td>
                        <td style="border: 1px solid black; padding: 8px; text-align: center">'.$row['description'].'</td>
                        <td>
                            <button onclick="DeleteUser('.$row['id'].')">Delete</button>
                        </td>
                    </tr>';
                }
            }
            $data .= '
                </table>
            </div>';
            
            header('Content-Type: text/html');
            exit( $data );
        break;
        case 'ascd':
            
            $data = '
            <div class="result">
                <table>
                    <tr>
                    <th>Title</th>
                    <th>Description</th>
                    </tr>';

            $fetch_query = "select * from app.add order by title";
            $fetch_run = mysqli_query($con, $fetch_query);

            if(mysqli_num_rows($fetch_run) > 0)
            {
                while($row = mysqli_fetch_array($fetch_run))
                {
                    $data .= '
                    <tr style="border: 1px solid black; padding: 8px; text-align: center">
                        <td style="border: 1px solid black; padding: 8px; text-align: center">'.$row['title'].'</td>
                        <td style="border: 1px solid black; padding: 8px; text-align: center">'.$row['description'].'</td>
                        <td>
                            <button onclick="DeleteUser('.$row['id'].')">Delete</button>
                        </td>
                    </tr>';
                }
            }
            $data .= '
                </table>
            </div>';
            
            header('Content-Type: text/html');
            exit($data);
        break;
        
        case 'dscd':
        
        break;
    }
}