原生的签到功能实现

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>sign</title>
</head>
<body>
<center>
    <input type="text" name="username">
    <button>签到</button><span id='span'></span>
    <div>
        <table id="box" border="1"></table>
    </div>
</center>
</body>
</html>
<script src="jquery.1.12.min.js"></script>
<script>
    $(function(){
        $('button').click(function(){
            var username=$(':text').val();
            $.ajax({
                type:'post',
                url:'admin.php',
                data:{username:username},
                dataType:'json',
                success:function(res){
                    if(res.success==1){
                        $('#span').html('签到成功');
                        var str='<tr><td>用户名</td><td>连续签到天数</td><td>总积分</td></tr>';
                        str+='<tr><td>'+res.msg.username+'</td><td>'+res.msg.count+'</td><td>'+res.msg.point+'</td></tr>';
                        $('#box').html(str);
                    }
                }
            })
        });
    })
</script>

<?php


require_once ('./pdo.php');
$username=1;
$param = [
];
$mypdo = Mypdo::getInstance($param);
//var_dump($mypdo);die;
$sqlQuery="select * from `user_point` where uid={$username}";
$row=$mypdo->fetchRow($sqlQuery);
//var_dump($row);
if($row){
    $sign_time=$row['sign_time'];
    $sign_time=strtotime($sign_time);
    $int=date('Y-m-d');
    $int=strtotime($int);//5
    $ints=$int+86400;  //6
    $int_s=$int-86400;  //4
    //当天已签到
    if($int<$sign_time&&$sign_time<$ints){
        // echo '您已签到';
    }
    //昨天未签到，积分，天数在签到修改为1
    if($sign_time<$int_s) {
        $count = 1;
        $point = 1;
        $sign_time = date('Y-m-d H:s:i');
        $sqlRow = "update user set count='$count',point='$point',sign_time='$sign_time' where username='$username'";
        $res = $mypdo->exec($sqlRow);
        // echo '签到成功修改为1';
    }
    //请签到
    if($int_s<$sign_time&&$sign_time<$int){
        $count=$row['count']+1;
        $point=$row['point']+1;
        $sign_time=date('Y-m-d H:s:i');
        $sqlupdate="update user set count='$count',point='$point',sign_time='$sign_time' where username='$username'";
        $res=$pdo->exec($sqlupdate);
        // echo '签到成功+1';
    }
}else{
    $count=1;
    $point=1;
    $sign_time=date('Y-m-d H:s:i');
    $sqlAdd="insert into user_point values (null,'$username','$count','$point','$sign_time')";
    $res=$mypdo->exec($sqlAdd);
    // echo '恭喜你签到成功----1';
}
$sqlEnd="select * from user where username='$username'";
$info=$pdo->query($sqlEnd)->fetch(PDO::FETCH_ASSOC);
echo json_encode(array('success'=>1,'msg'=>$info));die;