Question

我已经在php代码中设置了一个计数器，以便在每次下一次点击时增加mysql中的id值，但是当我刷新或重新加载页面时，值会自动增加是否有任何解决方案可以解决此问题或任何其他替代方案。

    <?php
    $db = mysqli_connect('localhost','root','root','rahul');

    $questions ="";
    $msg2 ="";
    $o1  ="" ;
    $o2  ="" ;
    $o3  ="" ;
    $o4  ="" ;
    $disable = "";
    $disable2 = "";

    session_start();

    if(empty($_SESSION['count']))
            $_SESSION['count'] = 0;     

    if(isset($_POST['sub1'])){      
       $ans = $_POST['ans'];
       $email = "rahul@gmail.com";          
       $order =  $_SESSION['count']+1;     
       echo $order;
       $_SESSION['count'] =  $order;

       $sql = (" SELECT * FROM qna WHERE id = $order ");

        $query = mysqli_query($db, $sql);
        $row=mysqli_fetch_array($query, MYSQLI_ASSOC);

        $questions = $row['questions'];
        $o1 = $row['o1'];
        $o2 = $row['o2'];
        $o3 = $row['o3'];
        $o4 = $row['o4'];

        $disable="";

    if($_SESSION['count']>5)
     {
    $disable = "disabled";
     }
    $disable2 = "";
        if($_SESSION['count']<=1)
     {
    $disable2 = "disabled";
     }

    //$sql2 =   "INSERT INTO result (id, answer, email) VALUES ('', '$ans', '$email') ".mysqli_error();
    /*
    $sql3 =   mysqli_query($db, "INSERT INTO result (answer, email) VALUES ('$ans', '$email')");

    if(mysqli_affected_rows($sql3)== true)
    {
        echo "inserted";
    }
    else
    {
        echo "not inserted";
    }
    */
    echo $ans. $email;    

     } 

     $sql4 = mysqli_query("select * from result");
     $row = mysqli_fetch_array($db, $sql4);
    // while()
     echo $row['id'];
     for($i=1;$i<=5;$i++)
     {

     }
    ?>

     <?php 

     if(isset($_POST['sub2'])){     
        $result2 = $_SESSION['count']-1;
        $_SESSION['count'] = $result2;    

     $sql = (" SELECT * FROM qna WHERE id = $result2 ");

        $query = mysqli_query($db, $sql);
        $row=mysqli_fetch_array($query, MYSQLI_ASSOC);
        $questions = $row['questions'];
        $o1 = $row['o1'];
        $o2 = $row['o2'];
        $o3 = $row['o3'];
        $o4 = $row['o4'];


    if($_SESSION['count']<=1){
       $disable2 = "disabled";
    }     
 }
 session_write_close();
?>
     <?php 
     if(isset($_POST['start'])){
        $order =  $_SESSION['count']+1;     
        echo $order;
        $_SESSION['count'] =  $order;      
        $sql = (" SELECT * FROM qna WHERE id = 1 ");        
        $query = mysqli_query($db, $sql);

        $row = mysqli_fetch_array($query, MYSQLI_ASSOC);
        $questions = $row['questions'];
        $o1 = $row['o1'];
        $o2 = $row['o2'];
        $o3 = $row['o3'];
        $o4 = $row['o4'];
        $disable="";

    if($_SESSION['count']>=5)
     {
    $disable = "disabled";
     }
    $disable2 = "";
        if($_SESSION['count']<=1){
           $disable2 = "disabled";
       }
    session_write_close();
     } 

     ?>

    <center><br><br><br>
    <form method="post">
    <input type="submit" name="start" value="start">
    </form>

    <a href="logout.php">Log out</a>
    <form action="" method="post" >
    <table border="1" height="300px" width="500px">
    <tr>
    <th colspan="2"><?php echo $questions; ?></th>
    </tr>

    <tr>
    <td><input type="radio"  name="ans" id="ans" value="<?php echo $o1; ?>"><?php echo $o1; ?></td>
    <td><input type="radio"  name="ans" value="<?php echo $o2; ?>"><?php echo $o2; ?></td>
    </tr>

    <tr>
    <td><input type="radio"  name="ans" value="<?php echo $o3; ?>"><?php echo $o3; ?></td>
    <td><input type="radio"  name="ans" value="<?php echo $o4; ?>"><?php echo $o4; ?></td>
    </tr>

    <tr colspan="2">
    <td><center><input type="submit" name="sub1" value="next" <?php echo $disable ?>> </td>
    <td><center><input type="submit" name="sub2" value="previous" <?php echo $disable2 ?>>
    <input type="submit" name="submit3" value="submit" > </td>
    </tr>

    </form>
    </table>

     <?php
     if(isset($_POST['submit3']))
     {
         $ans = $_POST['ans'];
        $email = "dummy";

    //$sql2 =   "INSERT INTO result (id, answer, email) VALUES ('', '$ans', '$email') ".mysqli_error();

    $sql3 =   mysqli_query($db, "INSERT INTO result (answer, email) VALUES ('$ans', '$email')");

    if(mysqli_affected_rows($sql3)== true)
    {
        echo "inserted";
    }
    else
    {
        echo "not inserted";
    }
    echo $ans. $email;

     } 

    ?>

Answer 1

当您重新加载网页时，您正在重新加载其POST（以及GET）数据（如果它在那里）。如果您要提交表单，则目标页面的标题中包含POST数据。因此，如果您重新加载此页面，就像您再次单击该按钮一样。

由于您已经在使用会话，因此有一种解决方法：

在表单中添加一个带有微时间戳的隐藏字段。每次页面加载时（每个用户），这个微时间戳都会有所不同 - 但是这个“新”时间戳只有在你使用按钮时才会被发布。当您只刷新页面时，您将使用旧时间戳重新加载所以你只需要保存比较最后一个时间戳（保存在会话变量中）和当前发布的时间戳。如果他们是平等的 - 页面刚刚刷新 - 如果他们不相等，那么你有一个新的时间戳由你的表单发送：

<?php
    session_start();

    if(!isset($_SESSION["timestamp"]))
        $_SESSION["timestamp"] = 0;

    if(!isset($_POST["timestamp"]))
        $_POST["timestamp"] = 0;

    // previous timestamp - saved in session variable:
    $prev_ts = $_SESSION["timestamp"];

    // currently posted timestamp:
    $post_ts = $_POST["timestamp"];

    if($prev_ts != $post_ts)
    {
        // code to increase your counter goes here.
        $feedback = "button pressed";
    }
    else
    {
        // do nothing when the page just got refreshed
        $feedback = "refreshed";
    }

    $_SESSION["timestamp"] = $post_ts;
?>

<!DOCTYPE html>
<html>
    <head>
    </head>
    <body>

        <?php echo $feedback; ?>

        <form action="<?php echo $_SERVER["PHP_SELF"]; ?>" method="POST">
            <input type="hidden" name="timestamp" value="<?php echo microtime(); ?>">
            <input type="submit" name="go" value="count">
        </form>
    </body>
</html>

在php中刷新和重新加载的计数器增加

1 个答案: