php - 通过减去乘数并使用 where 来更新查询

Question

我正在制作一个付费点击网站，并且希望通过减去和相乘的数字来更新查询。

我试图让用户购买一些广告包，他们输入观看次数和每次观看费用，然后当他们点击“提交”时，它应该在当前 session 中更新用户。但是，它不起作用:它正在更新所有用户的余额。

这是我的代码:

         <?php


      session_start();

       require_once '../constants/initSite.php';

          $siteConstant->addFile('css', 'account.css');
        echo $siteConstant->getHead();
      echo $siteConstant->getMenu();

if(isset($_SESSION['username']) && isset($_SESSION['password'])){

    require_once '../constants/class.DatabaseConstants.php';
    require_once '../class/class.DBase.php';

    $done = false;

$db = new DatabaseConstants();
$dBase = new DBase($db->getHost(), $db->getUser(), $db->getPass());
$dBase->setDatabaseName($db->getDb());

if(!$dBase->connectDatabase()){
    die('SQL ERROR at db class vd fn');
}
            $userQuery = mysqli_query($dBase->getDbobj(), "SELECT * FROM members WHERE username=\"".$_SESSION['username']."\"");
    if(mysqli_num_rows($userQuery)){
        $userData = mysqli_fetch_assoc($userQuery);
    }else{
        die('User Not Found!');
    }
               if(isset($_POST['submit'])){

 $adquery = 'INSERT INTO ads (Title,Link,ViewLimit,Pays) VALUES ("'.$_POST['title'].'","'.$_POST['link'].'","'.$_POST['views'].'","'.$_POST['pays'].'")';
    mysqli_query($dBase->getDbobj(), $adquery);
    if(!mysqli_affected_rows($dBase->getDbobj())<1){
        $done = true;
    }
           $id = 0;
    $qryE = mysqli_query($dBase->getDbobj(), 'SELECT Id FROM ads');
    while($dataE = mysqli_fetch_assoc($qryE)){
        $id = $dataE['Id'];
    }

    $userQueryE = mysqli_query($dBase->getDbobj(),'SELECT id FROM members');
    while($userDataE = mysqli_fetch_assoc($userQueryE)){
        mysqli_query($dBase->getDbobj(), 'INSERT INTO view (MemberId,AdId) VALUES ("'.$userDataE['id'].'","'.$id.'")');
    }
$userquery = ('UPDATE members SET balance=("'.$userData['balance'].'" - "'.$_POST['views'].'" * "'.$_POST['pays'].'") WHERE username="'.$_SESSION['username'].'"') ;

$userData = mysqli_fetch_assoc($userQuery);


       }





  ?>

 <center><img style="margin-bottom:5px"src="../image/ad468x60.png"/></center>

 <div id="maincontent" style="height:35em">
 <center>
   <ul id="menu2">
            <li><a href="../main/account.php">Account Details</a></li>
            <li><a href="../main/addaduser.php">Add Advertisement</a></li>
            <li><a href="../main/request.php">Request Payment</a></li>
            <li><a href="../main/refs.php">Referrals</a></li>
            <li><a href="../main/settings.php">Account Setting</a></li>
          </ul>

    <br>


</center>
 <center><p style="color:#0481b1;"><b><u>Add Advertisements</u></b></p></center>
      <form id="msform" method="POST" action="<?php echo $_SERVER["PHP_SELF"]; ?>">
            <center>
            <?php
                if(isset($_POST['submit']) && !$done){
                    echo '<h3 style="color:red;">Something went wrong!</h3>';
                }  

                if ($done){
                    echo '<h3 style="color:green;">Advertisement Added and is Active.</h3>';
                }
            ?>
        <?php 
                if($userData['balance'] < 5 ){
                    echo '<h3 style="color:red;">insufficient balance</h3></br>
                          <h2 style="color:red;text-decoration:underline">You currently have '.$userData['balance'].' '.$siteData['currency'].' </h2>
                          <center><h2 style="color:red">You do not have enough balance to add an advertissement.<br><br>You need to have at least 5 '.$siteData['currency'].' in your account balance to add an advertissement.</h2></center>';
                } 
                else {
                    echo'
                Title <input type="text" name="title" placeholder="Enter Site Title" required="true"/> <br><br>
                Link <input type="text" name="link" placeholder="Enter Site Link" required="true"/><br><br>
                Number of Viewers to send<input type="text" name="views" min="100" placeholder="Enter number of views to send(100 Views Minimum)" required="true"/><br><br>
                Reward per view<input type="text" name="pays" min="0.00001" placeholder="Enter reward per view(0.00001 '.$siteData['currency'].' Minimum)" required="true"/><br><br>
                <input type="submit" name="submit" class="NormButton" Value="Submit" /> ' ;
                    }
                ?>
            </center>
        </form>


   </div>

    <?php

      require_once '../main/footer.php';

       $dBase->closeDatabse();
          }else{
               header('location: index.php');

                   }

                            echo $siteConstant->getTail();

Answer 1

为什么你的where子句在SET之前检查这个

"UPDATE members SET balance=($userData['balance'] - $_POST['views'] * $_POST['pays']) WHERE username=$_SESSION['username']"