我设计了一个在线购物网站。
现在我想实施一个基于评级的系统，用户可以对不同的产品进行评级。
我已经以这样的方式编写代码，即从单个IP开始，速率只能被接受一次。这工作正常。
但后来我认为其他用户可能会从同一个IP登录。在这种情况下，系统应检查具有特定id的用户是否已经投票。
我被困在这里。
如果一个用户对该项目进行评级，那么他的id将存储在数据库中。接下来当具有不同用户ID的另一个用户登录他的id时没有被存储，或者更确切地说如何在数据库中存储多个用户ID，并检查他们是否先前已经对该项目进行了评级。我的数据库设计如下：
表名：评分
列-----
id（自动增量），user_id（int），total_votes（int 5），total_value（int 5），used_ips（长文本），date，product_id（varchar 20）
<?php
error_reporting(0);
include_once 'dbcon.php';
$prod_id=$_SESSION['rateproid'];
$userid_rating=$_SESSION['ud'];
//echo $prod_id;
// Get next auto increment value
$result = mysql_query("SHOW TABLE STATUS LIKE 'ratings'");
$row = mysql_fetch_array($result);
$nextId = $row['Auto_increment'];
?>
<?php
header("Cache-Control: no-cache");
header("Pragma: nocache");
include_once 'settings.php';
//$id_sent = preg_replace("/[^0-9]/","",$_REQUEST['id']);
//echo $id_sent;
$id_sent=$nextId;
$vote_sent = preg_replace("/[^0-9]/","",$_REQUEST['stars']);
$ip =$_SERVER['REMOTE_ADDR'] ;
connect();
$q=mysql_num_rows(mysql_query("select id from ratings where product_id='$prod_id'"));
//$q="SELECT count(*) from ratings where product_id='$prod_id'";
//echo $q;
echo $userid_rating;
if(!$q)
mysql_query("insert into ratings (id,date) values ($id_sent,curdate())");
if ($vote_sent > $units)
die("Sorry, vote appears to be invalid."); // kill the script because normal users will never see this.
//connecting to the database to get some information
$query = mysql_query("SELECT total_votes, total_value, used_ips FROM $rating_dbname.$rating_tableName WHERE product_id='$prod_id' ")or die(" Error: ".mysql_error());
$numbers = mysql_fetch_assoc($query);
$checkIP = unserialize($numbers['used_ips']);
$count = $numbers['total_votes']; //how many votes total
$current_rating = $numbers['total_value']; //total number of rating added together and stored
$sum = $vote_sent+$current_rating; // add together the current vote value and the total vote value
$tense = ($count==1) ? "vote" : "votes"; //plural form votes/vote
// checking to see if the first vote has been tallied
// or increment the current number of votes
($sum==0 ? $added=0 : $added=$count+1);
// if it is an array i.e. already has entries the push in another value
((is_array($checkIP)) ? array_push($checkIP,$ip) : $checkIP=array($ip));
$insertip=serialize($checkIP);
//IP check when voting
if(!isset($_COOKIE['rating_'.$id_sent])) {
//$voted=mysql_num_rows(mysql_query("SELECT used_ips FROM $rating_dbname.$rating_tableName WHERE used_ips LIKE '%".$ip."%' AND product_id='".$prod_id."' "));
$voted=mysql_num_rows(mysql_query("SELECT user_id FROM $rating_dbname.$rating_tableName WHERE user_id='".$userid_rating."' AND product_id='".$prod_id."' "));
} else
$voted=1;
if(!$voted) { //if the user hasn't yet voted, then vote normally...
if (($vote_sent >= 1 && $vote_sent <= $units)) { // keep votes within range, make sure IP matches
$update = "UPDATE $rating_tableName SET total_votes='".$added."', total_value='".$sum."', used_ips='".$insertip."', product_id='".$prod_id."', user_id='".$userid_rating."' WHERE id='$id_sent'";
$result = mysql_query($update);
if($result)
setcookie("rating_".$id_sent,1, time()+ 2592000);
}
} //end for the "if(!$voted)"
// these are new queries to get the new values!
$newtotals = mysql_query("SELECT total_votes, total_value, user_id FROM $rating_tableName WHERE product_id='$prod_id' ")or die(" Error: ".mysql_error());
$numbers = mysql_fetch_assoc($newtotals);
$count = $numbers['total_votes'];//how many votes total
$current_rating = $numbers['total_value'];//total number of rating added together and stored
$tense = ($count==1) ? "vote" : "votes"; //plural form votes/vote
// $new_back is what gets 'drawn' on your page after a successful 'AJAX/Javascript' vote
if($voted) {
$sum=$current_rating; $added=$count;
}
$new_back = array();
for($i=0;$i<5;$i++) {
$j=$i+1;
if($i<@number_format($current_rating/$count,1)-0.5)
$class="ratings_stars ratings_vote";
else
$class="ratings_stars";
$new_back[] .= '<div class="star_'.$j.' '.$class.'"></div>';
}
$new_back[] .= ' <div class="total_votes"><p class="voted"> Rating: <strong>'.@number_format($sum/$added,1).'</strong>/'.$units.' ('.$count.' '.$tense.' cast) ';
if(!$voted)
$new_back[] .= '<span class="thanks">Thanks for voting!</span> </p>';
else {
$new_back[] .= '<span class="invalid">Already voted for this item</span></p></div>';
}
$allnewback = join("\n", $new_back);
// ========================
$output = $allnewback;
echo $output;
?>