在上一篇随笔中已经将如何发布动态呈现了，那么现在来看一下剩下的评论动态、回复评论、删除动态和评论功能，这几个功能会有点绕~~~

一、思路如下：

（1）你发表动态之后，会有人评论这一条动态，当评论之后，你也会回复该评论；（此处评论要单独一张表，回复也要单独一张表）

（2）删除动态：会将动态连同评论、回复全部删除；删除评论：只会删除该条评论

二、在写代码之前，我还是想把流程说一遍：

（1）发表动态---评论---回复---再回复

（2）将上边的流程细化，我先在纸上写出，再上传，码字不能表达清楚（注意的是，我想要的功能的实现，并不是一模一样的哈）

三、还是先将代码分块解释，最后将主页面代码完全附上（含上一篇）

在上一篇中已经实现发布动态、弹出评论框，那么现在接着向下走：

分别看一下qqfriends,qqdongtai,qqpinglun，qqhuifu表,这是初始状态:

先以用户李四登录，由数据库qqfriends表中知道，李四的好友是zhangsan, 和zhaoliu,那么他的空间中显示的好友动态如下：

与上一篇相比，在这一篇中，谁登录的我用中文显示的：

<?php   session_start();   $uid = "";   if(empty($_SESSION["uid"]))   {    header("location:login.php");    exit;   }   $uid = $_SESSION["uid"];   require "../DB.class.php";   $db = new DB();   $sql = "select name from qqusers where uid="{$uid}"";   $name = $db->strquery($sql);   echo "欢迎："."<span class="qid" yh="{$uid}">{$name}</span>";   ?>

第一步：评论

1、评论张三的动态，点击“确定”后，就是第二张图了~

2、并将评论的内容写进数据库

 //定义空字符串，容纳评论的id    var code="";  $(".pl").click(function(){         code = $(this).attr("code"); //将评论的id重新赋值                     }) //将评论写进数据库 $("#tjpl").click(function(){  var plnr = $(".pldt").val();  var plid = code; //取发动态的id  $.ajax({  url:"pl-cl.php",  data:{plnr:plnr,plid:plid},  type:"POST",  dataType:"TEXT",  success:function(data){   alert("评论成功！");   window.location.href="main.php" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" ;  }        });             }) 

pl-cl.php页面<br><br>

<?phprequire "../DB.class.php";$db = new DB();session_start();$uid = $_SESSION["uid"];$plnr = $_POST["plnr"];$dtid = $_POST["plid"];$time = date("Y-m-d H:i:s", time());$sql = "insert into qqpinglun values ("","{$dtid}","{$uid}","{$plnr}","{$time}")";$db->query($sql,0);?>

查看qqpinglun表中是不是多了这一条 “为什么开心呢？”：

3、读取评论内容：

<!--读取评论内容--> <div id="dqpl"><?php $sql = "select * from qqpinglun"; $arr = $db->query($sql); foreach($arr as $v) {  $sql = "select * from qqdongtai where dtid="{$v[1]}"";  $arr2 = $db->query($sql);  foreach($arr2 as $m)  {   //取发动态的姓名   $sql = "select name from qqusers where uid="{$v[2]}"";   $name = $db->strquery($sql);   //若果是登录者评论则显示“我”   if($v[2]==$uid)   {    $name ="我";   }   //获取被评论者的姓名   $sql = "select name from qqusers where uid=(select uid from qqdongtai where dtid="{$v[1]}")";   $bpl = $db->strquery($sql);   echo "<div class="a"><span class="xm">{$name}</span>评论<span class="xm">{$bpl}</span>的动态:{$m[2]}<div>    <div class="b">{$v[3]}</div>   <div class="c">发表评论时间：{$v[4]}</div>   <div class="d"><button class="btn btn-primary hf" ids ="{$v[0]}">回复   </button><span><a href="scpl-cl.php?code={$v[0]}">删除评论</a></span></div>";  } }  ?>    </div>

第二步：回复

1、回复刚刚的评论：

2、将回复内容写进数据库

   //定义空字符串，容纳回复评论的id      var ids="";     $(".hf").click(function(){            ids = $(this).attr("ids"); //将评论的id重新赋值  //       alert((ids));        $("#mM").modal("show");                     })    //将回复评论写进数据库    $("#tjhf").click(function(){     var hfnr = $(".hfpl").val();//     alert(hfnr);//     alert(ids);     $.ajax({     url:"hf-cl.php",     data:{hfnr:hfnr,ids:ids},     type:"POST",     dataType:"TEXT",     success:function(data){     alert("回复成功！");    window.location.href="main.php" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" ;     }           });                }) 

　hf-cl.php页面

<?phprequire "../DB.class.php";$db = new DB();session_start();$uid = $_SESSION["uid"];$hfnr = $_POST["hfnr"];$cid = $_POST["ids"];$time = date("Y-m-d H:i:s", time());$sql = "insert into qqhuifu values ("","{$cid}","{$uid}","{$hfnr}","{$time}")";$db->query($sql,0);?>

　查看qqhuifu表，是不是多了一行呢？

3、将回复内容读出：

<div id="dqhf">      <!--取一次回复-->    <?php    $sql = "select * from qqhuifu where cid in (select cid from qqpinglun)";    $arr = $db->query($sql);    foreach($arr as $a)    {     $sql = "select * from qqpinglun where cid="{$a[1]}"";     $arr2 = $db->query($sql);     foreach($arr2 as $n)     {      //取评论动态的姓名      $sql = "select name from qqusers where uid="{$a[2]}"";      $name = $db->strquery($sql);      //若果是登录者评论则显示“我”      if($a[2]==$uid)      {       $name ="我";      }      //获取被回复评论的姓名      $sql = "select name from qqusers where uid=(select uid from qqpinglun where cid="{$a[1]}")";      $bpl = $db->strquery($sql);      echo "<div class="a"><span class="xm">{$name}</span>回复<span class="xm">{$bpl}</span>的评论:{$n[3]}<div>       <div class="b">{$a[3]}</div>      <div class="c">回复时间：{$a[4]}</div>      <div class="d"><button class="btn btn-primary hf" ids ="{$a[0]}">回复      </button><span><a href="schf-cl.php?code={$a[0]}">删除回复</a></span></div>";      }     }    ?>   </div>

回复内容已经显示了：

第三步：删除

1、删除动态：（含评论和回复）

scdt-cl.php

<?php$code = $_GET["code"];require "../DB.class.php";$db = new DB();$sql = "delete from qqdongtai where dtid="{$code}"";$db->query($sql,0);$sql2 = "delete from qqpinglun where dtid="{$code}"";$db->query($sql2,0);$sql3 = "delete from qqhuifu where cid=(select cid from qqpinglun where dtid="{$code}")";$db->query($sql3,0);header("location:main.php");?>

2、删除评论：（含回复）

scpl-cl.php

<?php$code = $_GET["code"];require "../DB.class.php";$db = new DB();$sql2 = "delete from qqpinglun where cid="{$code}"";$db->query($sql2,0);$sql3 = "delete from qqhuifu where cid="{$code}"";$db->query($sql3,0);header("location:main.php");?>

3、删除回复：（只自己）

schf-cl.php

<?php$code = $_GET["code"];require "../DB.class.php";$db = new DB();$sql2 = "delete from qqpinglun where cid="{$code}"";$db->query($sql2,0);$sql3 = "delete from qqhuifu where cid="{$code}"";$db->query($sql3,0);header("location:main.php");?>

　关于删除就不依次试了~~~注意包含关系就好了

主页面全部代码：

<!DOCTYPE html><html>  <head>  <meta charset="UTF-8">  <title></title>   <!--引入bootstrap的css文件-->  <link type="text/css" rel="stylesheet" href="../bootstrap-3.3.7-dist/css/bootstrap.min.css" rel="external nofollow" />  <!--引入js包-->  <script src="../jquery-3.2.0.js"></script>  <!--引入bootstrap的js文件-->  <script src="../bootstrap-3.3.7-dist/js/bootstrap.min.js"></script>  <style>   #body{    height: auto;    width: 1000px;    margin: 0px auto;   }   #xdt{    height: 200px;    width:1000px;     border: 1px solid cadetblue;    }    /*动态和评论div*/    .fdt{    position: relative;      width: 1000px;    }    /*读取内容div*/     #nr{     width: 1000px;     }    /*谁发表动态样式*/    .a{    float: left;    min-height:40px;    width: 1000px;    background-color: goldenrod;    }    /*姓名*/    .xm{    font-size: 18px;    color: brown;    font-weight: bold;    }    /*发表动态样式内容*/    .b{    float: left;    text-align: left;    height:100px;    line-height: 50px;    width: 100%;    background-color: greenyellow;    }    /*发表时间与回复删除样式*/    .c{    height:30px;    width: 800px;    float: left;    font-size: 12px;    text-align:right;    background-color: gainsboro;     }     /*弹出模态框评论框*/    .d{    height:30px;    width: 200px;    float: left;    font-size: 15px;    text-align:center;    background-color: gainsboro;     }     /*读取评论div*/     #dqpl{     width: 1000px;     }    #dqhf    {     width: 1000px;     }  </style>      </head> <body>  <div id="body">  <?php   session_start();   $uid = "";   if(empty($_SESSION["uid"]))   {    header("location:login.php");    exit;   }   $uid = $_SESSION["uid"];   require "../DB.class.php";   $db = new DB();   $sql = "select name from qqusers where uid="{$uid}"";   $name = $db->strquery($sql);   //这种方法可以取到uid。   echo "欢迎："."<span class="qid" yh="{$uid}">{$name}</span>";   ?>  <!--写动态-->  <div id="xdt">   <p>发表动态：</p>   <textarea cols="100px" rows="5px" name="xdt" class="xdt"></textarea>   <input type="submit" value="发表" id="fb" />    </div>  <!--动态内容结束-->  <!--容纳动态内容-->   <div class="fdt">   <p style="color: brown; font-family: "微软雅黑";font-weight: bold;font-size: 20px; margin-bottom: 20px; margin-top: 20px;">朋友动态：<p>   <!--读取动态内容-->   <div id="nr">    <?php    $date = date ("Y-m-d H:i:s");    $sql = "select * from qqdongtai where uid="{$uid}" or uid in (select uid from qqfriends where fname =(select name from qqusers where uid="{$uid}")) order by time desc";    //echo $sql;    $arr = $db->query($sql);//    var_dump($arr);    foreach($arr as $v)    {     $sql = "select name from qqusers where uid="{$v[1]}"";     $name = $db->strquery($sql);     if($v[1]==$uid)     {      $name = "我";     }     echo "<div class="a"><span class="xm">{$name}</span>发表动态：</div>     <div class="b">{$v[2]}</div>     <div class="c">发表动态时间:{$v[3]}</div>     <div class="d"><button class="btn btn-primary pl" data-toggle="modal" data-target="#myModal" code ="$v[0]">评论</button>      <span><a href="scdt-cl.php?code={$v[0]}">删除动态</a></span></div>";    }    ?>   </div>        <!--读取评论内容-->    <div id="dqpl">   <?php    $sql = "select * from qqpinglun";    $arr = $db->query($sql);    foreach($arr as $v)    {     $sql = "select * from qqdongtai where dtid="{$v[1]}"";     $arr2 = $db->query($sql);     foreach($arr2 as $m)     {      //取发动态的姓名      $sql = "select name from qqusers where uid="{$v[2]}"";      $name = $db->strquery($sql);      //若果是登录者评论则显示“我”      if($v[2]==$uid)      {       $name ="我";      }      //获取被评论者的姓名      $sql = "select name from qqusers where uid=(select uid from qqdongtai where dtid="{$v[1]}")";      $bpl = $db->strquery($sql);      echo "<div class="a"><span class="xm">{$name}</span>评论<span class="xm">{$bpl}</span>的动态:{$m[2]}<div>       <div class="b">{$v[3]}</div>      <div class="c">发表评论时间：{$v[4]}</div>      <div class="d"><button class="btn btn-primary hf" ids ="{$v[0]}">回复      </button><span><a href="scpl-cl.php?code={$v[0]}">删除评论</a></span></div>";     }    }     ?>       </div>   <!--读取回复的内容-->    <div id="dqhf">     <?php    $sql = "select * from qqhuifu where cid in (select cid from qqpinglun)";    $arr = $db->query($sql);//    var_dump($arr);    foreach($arr as $a)    {     $sql = "select * from qqpinglun where cid="{$a[1]}"";     $arr2 = $db->query($sql);//     var_dump($arr2);     foreach($arr2 as $n)     {      //取评论动态的姓名      $sql = "select name from qqusers where uid="{$a[2]}"";      $name = $db->strquery($sql);      //若果是登录者评论则显示“我”      if($a[2]==$uid)      {       $name ="我";      }      //获取被回复评论的姓名      $sql = "select name from qqusers where uid=(select uid from qqpinglun where cid="{$a[1]}")";      $bpl = $db->strquery($sql);      echo "<div class="a"><span class="xm">{$name}</span>回复<span class="xm">{$bpl}</span>的评论:{$n[3]}<div>       <div class="b">{$a[3]}</div>      <div class="c">回复时间：{$a[4]}</div>      <div class="d"><button class="btn btn-primary hf" ids ="{$a[0]}">回复      </button><span><a href="schf-cl.php?code={$a[0]}">删除回复</a></span></div>";      }     }    ?>   </div>  </div>  <!-- 评论模态框（Modal） -->   <div class="modal fade" id="myModal" tabindex="-1" role="dialog" aria-labelledby="myModalLabel" aria-hidden="true">    <div class="modal-dialog">     <div class="modal-content">      <div class="modal-header">       <button type="button" class="close" data-dismiss="modal" aria-hidden="true">×</button>       <h4 class="modal-title" id="myModalLabel">评论</h4>      </div>      <textarea class="modal-body pldt" cols="80px"></textarea>      <div class="modal-footer">       <button type="button" class="btn btn-default" data-dismiss="modal">关闭</button>       <button type="button" class="btn btn-primary" id="tjpl">提交评论</button>      </div>     </div>    </div>   </div>    <!--模态框结束-->      <!-- 回复模态框（Modal） -->   <div class="modal fade" id="mM" tabindex="-1" role="dialog" aria-labelledby="myModalLabel" aria-hidden="true">    <div class="modal-dialog">     <div class="modal-content">      <div class="modal-header">       <button type="button" class="close" data-dismiss="modal" aria-hidden="true">×</button>       <h4 class="modal-title" id="myModalLabel">回复</h4>      </div>      <textarea class="modal-body hfpl" cols="80px"></textarea>      <div class="modal-footer">       <button type="button" class="btn btn-default" data-dismiss="modal">关闭</button>       <button type="button" class="btn btn-primary" id="tjhf">提交回复</button>      </div>     </div>    </div>   </div>    <!--模态框结束-->   </div>  </body></html>   <script>//ajax方法：刷新页面时将内容读取出来，并按发表时间读出来//    $.ajax({//     url:"sx-cl.php",//     dataType:"TEXT",//     success:function(data){//      var hang = data.trim().split("|");//      var str="";//      for(var i=0;i<hang.length;i++)//      {//       var lie = hang[i].split("^");        //        str = str + "<div class="a"><span class="xm">"+lie[1]+"</span>发表动态：</div><div class="b"><p>"+lie[2]+"</p><div class="c">发表动态时间："+lie[3]+"</div>";              //       str =str+"<div id="d"><button class="btn btn-primary pl" data-toggle="modal" data-target="#myModal" code =""+lie[0]+"">评论</button><span><a href="del.php?code="+lie[0]+"">删除动态</a></span></div>";//      }//      $("#nr").html(str);//     //点击“评论按钮”实现将code值传到模态框的“提交按钮”//     //为什么放在此处：因为ajax是异步的，如果不放在此处会加不上点击事件//       $(".pl").click(function(){//        code = $(this).attr("code"); //将评论的id重新赋值             //       })     //     } //    }); //    //php方法： 当发表动态时，将动态内容写进数据库，并刷新页面    $("#fb").click(function(){    var dt= $(".xdt").val();    var uid = $(".qid").attr("yh");    $.ajax({     url:"main-cl.php",     data:{dt:dt},     type:"POST",     dataType:"TEXT",     success:function(data){      alert("发表动态成功！");      window.location.href="main.php" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" ;     }     });    })     //定义空字符串，容纳评论的id       var code="";     $(".pl").click(function(){            code = $(this).attr("code"); //将评论的id重新赋值                        })    //将评论写进数据库    $("#tjpl").click(function(){     var plnr = $(".pldt").val();     var plid = code; //取发动态的id//    alert(plnr);//    alert(plid);      $.ajax({     url:"pl-cl.php",     data:{plnr:plnr,plid:plid},     type:"POST",     dataType:"TEXT",     success:function(data){      alert("评论成功！");      window.location.href="main.php" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" ;     }           });                })    //定义空字符串，容纳回复评论的id      var ids="";     $(".hf").click(function(){            ids = $(this).attr("ids"); //将评论的id重新赋值  //       alert((ids));        $("#mM").modal("show");                     })    //将回复评论写进数据库    $("#tjhf").click(function(){     var hfnr = $(".hfpl").val();//     alert(hfnr);//     alert(ids);     $.ajax({     url:"hf-cl.php",     data:{hfnr:hfnr,ids:ids},     type:"POST",     dataType:"TEXT",     success:function(data){     alert("回复成功！");    window.location.href="main.php" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" ;     }           });                })  </script>

到此处为止，动态的发布、动态的评论、动态的回复、动态的删除都已经写完了，但是有个问题还还还没解决完，也就是回复的回复问题。请看下面的简图：

也就是回复表中有一部分是回复的评论，而剩余的部分则是回复的回复（有点绕）想看的就继续关注（下）未完待续~~~

先总结一下遇到的问题：

（1）为什么ajax输出的button添加不上点击事件？

     因为ajax是异步ajax，所以要紧接其后。

（2）为什么取不到button的值------this

（3）一个php页面中，什么时候用ajax？什么时候用php？

    在这个实例中,我用ajax将数据写进数据库；用php从数据库读取内容。（上一篇中，动态是用ajax读取的，在这一篇中，两种方法都有，详情请看全部代码）

（4）最后，逻辑清晰很关键，尤其是表与表之间的关联。