PHP development red and blue voting function tutorial backend page

Create vote.php file

The front end requests the background vote.php, and vote.php will connect to the database according to the received parameters. Call related functions.

##The code is as follows

<?php
header("Content-type:text/html;charset=utf-8");
$action = $_GET['action'];
$id = 1;
$ip = get_client_ip();//获取ip
if($action=='red'){//红方投票
    vote(1,$id,$ip);
}elseif($action=='blue'){//蓝方投票
    vote(0,$id,$ip);
}else{
    echo jsons($id);
}
function vote($type,$id,$ip){
    $conn=mysqli_connect("localhost","root","root","vote");
    $ip_sql="SELECT ip from votes_ip where vid='$id' and ip='$ip'";
    $que=mysqli_query($conn,$ip_sql);
    $count=mysqli_num_rows($que);
    if($count==0){//还没有投票
        if($type==1){//红方
            $sql = "update votes set likes=likes+1 where id=".$id;
        }else{//蓝方
            $sql = "update votes set unlikes=unlikes+1 where id=".$id;
        }
        mysqli_query($conn,$sql);
        $sql_in = "insert into votes_ip (vid,ip) values ('$id','$ip')";
        $result = mysqli_query($conn,$sql_in);
        if($result > 0){
            echo jsons($id);
        }else{
            $arr['success'] = 0;
            $arr['msg'] = '操作失败，请重试';
            echo json_encode($arr);
        }
    }else{
        $arr['success'] = 0;
        $arr['msg'] = '已经投票过了';
        echo json_encode($arr);
    }
}
function jsons($id){
    $conn=mysqli_connect("localhost","root","root","vote");
    $que_sql="select * from votes where id=".$id;
    $query = mysqli_query($conn,$que_sql);
    $row = mysqli_fetch_array($query);
    $red = $row['likes'];
    $blue = $row['unlikes'];
    $arr['success']=1;
    $arr['red'] = $red;
    $arr['blue'] = $blue;
    $red_percent = round($red/($red+$blue),3);
    $arr['red_percent'] = $red_percent;
    $arr['blue_percent'] = 1-$red_percent;
    return json_encode($arr);
}
//获取用户真实IP
function get_client_ip() {
    if (getenv("HTTP_CLIENT_IP") && strcasecmp(getenv("HTTP_CLIENT_IP"), "unknown"))
        $ip = getenv("HTTP_CLIENT_IP");
    else
        if (getenv("HTTP_X_FORWARDED_FOR") && strcasecmp(getenv("HTTP_X_FORWARDED_FOR"), "unknown"))
            $ip = getenv("HTTP_X_FORWARDED_FOR");
        else
            if (getenv("REMOTE_ADDR") && strcasecmp(getenv("REMOTE_ADDR"), "unknown"))
                $ip = getenv("REMOTE_ADDR");
            else
                if (isset ($_SERVER['REMOTE_ADDR']) && $_SERVER['REMOTE_ADDR'] && strcasecmp($_SERVER['REMOTE_ADDR'], "unknown"))
                    $ip = $_SERVER['REMOTE_ADDR'];
                else
                    $ip = "unknown";
    return ($ip);
}
?>