Question

我正在研究投票系统而且我坚持确保某人只能投票一次。我看了存储IP，但我读到像大学这样的地方使用的知识产权很少，所以如果一个人投票，大部分大学都被排除在投票之外。目前我使用cookies，这是很好的，直到人们意识到我正在使用cookie。然后他们很容易删除cookie并再次投票。有没有可靠的方法存储用户的投票并确保他们不能再投票？这是我目前的投票脚本：

<?php
include("config.php");

//Checks URL for any GET variables and removes them.
$url = $_POST['url'];
$arr = explode("?", $url, 2);
$url = $arr[0];


//Makes sure someone didn't just go to /vote.php.
if (empty($_POST['url'])) {
    print '<script>window.location = "errorpage";</script>';
} else {

//Gets unique ID number for specific match up.
$idnumber = $_POST['id'];

//Checks to see if there is a cookie by the name of the unique matchup ID.
if (!empty($_COOKIE[$idnumber])) {

    //If voted, go back and display already voted error.    
    print '<script> window.location = "'.$url.'?error=voted";</script>';

} else {

    //If user doesn't have the cookie, then set it to expire in 1 year. 
    setcookie("$idnumber", "1", strtotime( '+1 year' ));

//Sets variable for a_vote or b_vote.
$voteRow = $_POST['hiddenvote'];

//Array of allowed values for column name.
$allowed = array("a_vote","b_vote");

//If $voteRow is not a_vote or b_vote, then go to error page.
if(!in_array($voteRow, $allowed)) {
    print '<script>window.location = "errorpage";</script>';
} else {

    //Gets current votes and adds one for new value. 
    foreach($db->query("SELECT $voteRow FROM votes WHERE matchup = '$idnumber'") as $row) {
                $votes = $row[$voteRow];
             }  

             $newvotes = $votes + 1;

//Update query to send new vote amount.
$sql = "UPDATE `votes` SET $voteRow = :newvotes WHERE `matchup` = :id";
 $statement = $db->prepare($sql);
 $statement->bindValue(":newvotes", $newvotes);
 $statement->bindValue(":id", $idnumber);
 $count = $statement->execute();
 $db = null;

//Go to vote success page.
print '<script type="text/javascript">window.location = "'.$url.'?vote=success";</script>'; 
}
}
}
?>

PHP投票系统 - 确保一个人只能投票一次

0 个答案: