php - mysql_data_seek 不工作

Question

我的代码是，

$query3     =   "SELECT * FROM db_exam_skip WHERE user='$session'";
$result3        =   mysql_query($query3) or die(mysql_error());
$length3        =   mysql_num_rows($result3);
while($rows3    =   mysql_fetch_array($result3))
{
    $query1 =   "SELECT * FROM db_exam_questions WHERE id='$rows3[ques_id]'";
    $result1   =    mysql_query($query1) or die(mysql_error());
    $length1   =    mysql_num_rows($result1);
}

if(isset($_POST['next']))
    {
        if(isset($_SESSION['list']))
        {
            mysql_data_seek($result1,$_SESSION['list']);
        }
        else
        {
            $list       =   $_POST['list'];
            mysql_data_seek($result1,$list);
        }
    }

<?php
        while($rows1    =   mysql_fetch_row($result1))
        {
            $start  =   $rows1[0];
            $_SESSION['start']  =   $start;
    ?>
 <form action="" method="post">
    <p style="font-size:20px;font-weight:bold"><?php echo $rows1[5]; ?></p>
    <ul style="list-style-type:none">
        <input type='hidden' name='number' value='<?php echo $_SESSION['order']++; ?>' />
        <input type='hidden' name='list' value='<?php echo $_SESSION['list']++; ?>' />
        <input type='hidden' name='ques_id' value='<?php echo $rows1[0]; ?>' />
        <input type='hidden' name='correct' value='<?php echo $rows1[10]; ?>' />
        <li><input type="radio" name="answer" value="1" /> <?php echo $rows1[6]; ?> <br><br>
        <input type="radio" name="answer" value="2" /> <?php echo $rows1[7]; ?> <br><br>
        <input type="radio" name="answer" value="3" /> <?php echo $rows1[8]; ?> <br><br>
        <input type="radio" name="answer" value="4" /> <?php echo $rows1[9]; ?> <br></li>
    </ul>
  <input type="submit" class="button4" value="Next" name="next" />
</form>
    <?php
    break;
        }
    ?>

我的问题是，在加载第一个问题后，当我按下下一步按钮加载第二个问题时，出现以下错误。

警告:mysql_data_seek(): Offset 2 is invalid for MySQL result index 8 (or the query data is unbuffered) in C:\wamp\www\Albert\ICAMS\start_skip_question.php on line 15

我已经尝试了很多方法来解决这个错误。但直到现在都没有成功。有什么方法可以解决。任何帮助将不胜感激。

谢谢。

Answer 1

我猜结果集是空。我认为查询返回空集。 如果结果集为空，您将收到此错误 检查 PHP DOCS

首先检查你是否从结果中得到 Ant 行

if (mysqli_num_rows($sql) > 0)
{
}