Javascript [html、php、mysql]如何使用输入或按钮在当前行的基础上动态获取上一行，并在文本区域中显示

我现在正在构建一个论坛，我将有一个带有“编辑”按钮的导航栏，供用户编辑他们以前的评论

        <div class="collapse navbar-collapse" id="bs-example-navbar-collapse-1">
            <div>
                <ul class="nav navbar-nav navbar-left">
                    <li><a href="#quest"> Post a Question</a></li>
                    <li><a href="#edit"> Edit comment</a></li>
                </ul>
                <ul class="nav navbar-nav navbar-right">
                    <li><a href="userprofile.php" ><span class="glyphicon glyphicon-user"></span> <?php echo $username;?></a></li>
                    <li><a href="logout.php"><span class="glyphicon glyphicon-log-out"></span> Logout</a></li>
                </ul>
            </div>
        </div>

下面是我如何在页面上显示之前发布的所有评论，但我不知道这是否有帮助

        <div class="panel-body">
            <?php
                $id = $_GET['post_id'];
                $sql = mysql_query("SELECT * from tblpost as tp join category as c on tp.cat_id=c.cat_id where tp.post_Id='$id' ");
                if($sql==true){
                    while($row=mysql_fetch_assoc($sql)){
                        extract($row);
                        if($user_Id==009){
                            echo "<label>Topic Title: </label> ".$title."<br>";
                            echo "<label>Topic Category: </label> ".$category."<br>";
                            echo "<label>Date time posted: </label> ".$datetime;
                            echo "<p class='well'>".$content."</p>";
                            echo "<label>Posted By: </label> Admin";
                        }else{
                            $sel = mysql_query("SELECT * from tbluser where user_Id='$user_Id' ");
                            while($row=mysql_fetch_assoc($sel)){
                                extract($row);
                                echo "<label>Topic Title: </label> ".$title."<br>";
                                echo "<label>Topic Category: </label> ".$category."<br>";
                                echo "<label>Date time posted: </label> ".$datetime;
                                echo "<p class='well'>".$content."</p>";
                                echo '<label>Posted By: </label>'.$fname.' '.$lname;
                            }
                        }
                    }
                }
            ?>

我建议您从
mysql
更新到
mysqli
，因为
mysql
已贬值。另外，如果不清除/检查
$id
变量而将其放入SQL查询，则会使数据库面临SQL注入的风险。为了安全起见，我知道real_escape_string（）和strip_tag（）函数，但这不是我现在的重点，因为它将仅在我的本地主机中。。。
<div class="my-quest" id="edit">
    <div>
        <h3>Edit Comment</h3>
        <form method="POST" action="editcomment.php">
            <?php
                $postid= $_GET['post_id'];
                $comment = mysql_query("SELECT * from tblcomment as c join tbluser as u on c.user_Id=u.user_Id where post_Id='$postid' and comment_Id in ( select max(comment_Id) from tblcomment)");
                $rowedit=mysql_fetch_assoc($comment)
            ?>
            <textarea type="text" class="form-control" name="editcommenttxt"><?php echo $rowedit['comment']?></textarea><br>
            <input type="hidden" name="editpostid" value="<?php echo $_GET['post_id']; ?>">
            <input type="hidden" name="edituserid" value="<?php echo $_SESSION['user_Id']; ?>">
            <input type="submit" name="editcomment" class="btn btn-success pull-right" value="Edit">
        </form>
        <br>
        <hr>
        <a href="" class="pull-right">Close</a>
    </div>
</div>

<?php 
include "../functions/db.php";
if(isset($_POST['editcomment'])){
    extract($_POST);

    $check = mysql_query("select max(comment_Id) as maxid from tblcomment where user_Id = '$edituserid'");
    $check2 = mysql_fetch_assoc($check);
    $sql = "Update tblcomment set comment='$editcommenttxt' where post_Id = '$editpostid' and comment_Id = '".$check2['maxid']."'";

    $update=mysql_query($sql);

    if($update==true) {
        echo '<script language="javascript">';
        echo 'alert("Post Successfully")';
        echo '</script>';
        echo '<meta http-equiv="refresh" content="0;url=content.php?post_id='.$editpostid.'" />';
    } else {
        echo "Sorry error occur, cannot edit post!";
    }
}
?>