首先我们需要知道这个功能逻辑流程是什么，其实很简单。首先没点赞的时候显示默认的HTML样式，当点赞就用PHP+AJAX读取数据库内的字段，返回判断是否已经存在，存在代表已经点赞，不存在就写入，然后更改HTML样式。
下面详细讲解，首先需要建立一个数据库，分为两个数据表。一个进行对点赞数的统计，一个进行不同用户的点赞记录。
写PHP接口，首先连接这个数据库。
$con = new mysqli('localhost','root','','test');
if (!$con)
{
die('连接数据库失败，失败原因：' . mysqli_error());
}else {
// echo "连接成功";
}对用户是否点赞进行判断（操作页面）
对数据库的信息进行提取
//假设用户编号为1 $uId="1"; //假设赞编号为1 $zanId="1"; //查找赞id为1的点赞数 $count=mysqli_query($con, "SELECT count FROM zanCount WHERE zanId=$zanId "); $countResult=mysqli_fetch_array($count); $countZan=$countResult['count']; //查找改用户是否对赞id为1 点赞 $uIdLike=mysqli_query($con, "SELECT * FROM zanRecord WHERE uId=$uId "); $result=mysqli_fetch_array($uIdLike);
对用户是否点赞进行判断，并输出不同的html
//点赞
if (isset($result))
{
$showZan.=<<<html
<div class="dolikeDIV" id="dolikeDIV">
<button id="dolike" οnclick="zanDel()"></button>
<span id="zan">$countZan</span>
</div>
html;
}
//没点赞
else
{
$showZan.=<<<html
<div class="dolikeDIV" id="dolikeDIV">
<button id="donolike" οnclick="zan()"></button>
<span id="zan">$countZan</span>
</div>
html;
}
echo $showZan;
?>#dolike, #donolike
{
width:30px;
height:30px;
margin-left:20px;
float:left;}
#donolike
{
background:url(./images/nolike.png);
background-size:30px 30px;
}
#dolike
{
background:url(./images/like.png);
background-size:30px 30px;
}调用的ajax方法
传递需要的数据，这里传递的时zanId 和uId
记得引入jq文件
点赞
function zan()
{
$.ajax({
type:"POST",
url:"./likeSever.php",
data:{'zanId':$("#zanId").val(),'uId':$("#uId").val()},
success:function(text){
$("#dolikeDIV").html(text);
}
});
}取消点赞
function zanDel()
{
$.ajax({
type:"POST",
url:"./disSever.php",
data:{'zanId':$("#zanId").val(),'uId':$("#uId").val()},
success:function(text){
$("#dolikeDIV").html(text);
}
});
}点赞处理
//更新赞总数的数据 mysqli_query($con,"UPDATE zanCount SET count = count+1 WHERE zanId=$zanId"); //添加一条点赞记录 mysqli_query($con,"INSERT INTO zanRecord(zanId,uId) VALUES($zanId, $uId); "); //查找赞的总数 @$count=mysqli_query($con, "SELECT count FROM zanCount WHERE zanId=$zanId "); @$countResult=mysqli_fetch_array($count); @$countZan=$countResult['count']; //更改输出的html $show=""; $show=<<<html <button id="dolike" οnclick="zanDel()"></button> <span id="zan">$countZan</span> html; echo $show;
取消点赞处理
//更新赞总数的数据 mysqli_query($con,"UPDATE zanCount SET count = count-1 WHERE zanId=$zanId"); //添加一条点赞记录 mysqli_query($con,"DELETE FROM zanRecord WHERE zanId=$zanId AND uId=$uId "); //查找赞的总数 @$count=mysqli_query($con, "SELECT count FROM zanCount WHERE zanId=$zanId "); @$countResult=mysqli_fetch_array($count); @$countZan=$countResult['count']; //更新html $show=""; $show.=<<<html <button id="donolike" οnclick="zan()"></button> <span id="zan">$countZan</span> html; //更新赞总数的数据 mysqli_query($con,"UPDATE zanCount SET count = count-1 WHERE zanId=$zanId"); //添加一条点赞记录 mysqli_query($con,"DELETE FROM zanRecord WHERE zanId=$zanId AND uId=$uId "); //查找赞的总数 @$count=mysqli_query($con, "SELECT count FROM zanCount WHERE zanId=$zanId "); @$countResult=mysqli_fetch_array($count); @$countZan=$countResult['count']; //更新html $show=""; $show.=<<<html <button id="donolike" οnclick="zan()"></button> <span id="zan">$countZan</span> html;