如何限制用户两次投票 [英] How can I restrict user from voting twice
本文介绍了如何限制用户两次投票的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
我是php编码的新手，我正在尝试为我的学校开发一个在线投票系统作为我的最终项目。已完成所有编码和设计，一切正常，但当注册用户注销和登录时，用户可以多次投票并继续阅读。我想知道如何限制用户两次投票，所以第二次让用户登录，它应该将用户重定向到另一个页面
我尝试了什么：
I'm new on php coding and I'm trying to develop an online voting system for my school as my final project. Have done all the coding and designing , everything is working fine, but when the registered user logout and login, the user can be able to vote more than once and it keeps reading. Please I want to know how to restrict user from voting twice, so incase the user login in the second time, it should redirect the user to another page
What I have tried:
<?php
$con = mysqli_connect("localhost", "root", "password007", "university portal");
if(isset($_POST['radio'])){
mysqli_query($con, "update candidate set Vote=Vote+1 where UserID=$_POST[radio]");
$insertGoTo = "Voting2.php";
header(sprintf("Location: %s", $insertGoTo));
}
?>
<!doctype html>
<meta charset="utf-8">
<title>Voting
function preventBack(){window.history.forward();}
setTimeout("preventBack()", 0);
window.onunload = function() {null};
<div id="Holder">
<div id="Header">
<a href="Home.php"></a>
</div>
<div id="NavBar">
<ul>
<li><a href="Home.php">Home</a></li>
<li><a href="Login.php">Student Portal</a>
<ul>
<li><a href="Login.php">Login</a></li>
<li><a href="Candidate%20Profile.php">Candidates Profile</a></li>
</ul>
</li>
<li><a href="Admin.php">Admin</a></li>
<li><a href="About%20Site.php">About Us</a>
<ul>
<li><a href="About%20Site.php">About Site</a></li>
<li><a href="Contact%20Us.php">Contact Us</a></li>
</ul>
</li>
</ul>
</div>
<div id="Content">
<div id="PageHeading">
<h1> </h1>
<h1> </h1>
<h1>President</h1>
</div>
<div id="ContentLeft">
<h2>Your Message Here</h2>
<h6>Note: vote wisely, once you've voted you cannot go back.</h6>
</div>
<div id="ContentRight">
<table width="400" border="0" align="center"><tbody><tr><td>
<table border="0" align="center"><tbody><tr><td><h6>For President</h6></td></tr></tbody></table></td></tr><tr><td> </td></tr><tr><td>
<table width="397" border="0"><tbody><tr><td width="102"></td><td width="282"><h6>
OBINNA DANIEL CHUKWUKA</h6></td></tr></tbody></table></td></tr><tr><td> </td></tr><tr><td>
<table width="397" border="0"><tbody><tr><td width="101"></td><td width="286"><h6>
ABUBAKA KAYODE </h6></td></tr></tbody></table></td></tr><tr><td> </td></tr><tr><td>
<table border="0" align="center"><tbody><tr><td></td></tr></tbody></table></td></tr><tr><td> </td></tr></tbody></table>
</div>
</div>
<div id="Footer"></div>
</div>
<p> </p>
<?php
mysql_free_result($voting);
?>
推荐答案
con = mysqli_connect（ localhost， root， password007，< span class =code-string> university portal）;
if（isset（
con = mysqli_connect("localhost", "root", "password007", "university portal"); if(isset(
_POST [' radio']））{
mysqli_query（
_POST['radio'])){ mysqli_query(
con， 更新候选集投票=投票+ 1，其中UserID =
con, "update candidate set Vote=Vote+1 where UserID=
这篇关于如何限制用户两次投票的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
查看全文
