注意：未定义的索引：日期

Question

  

注意：未定义的索引：第26行的C：\ xampp \ htdocs \ StudentAttendanceSystem \ show_attendance.php中的日期

<?php $result=mysqli_query($con,"SELECT * FROM attendance_records where date='$_POST[date]'"); //this is line 26
$serialnumber=0;
$counter=0;
while($row=mysqli_fetch_array($result))
{
    $serialnumber++; ?>
    <tr>
    <td>  <?php echo $serialnumber  ?>  </td>
    <td>  <?php echo $row['student_name']  ?>  </td>
    <td>  <?php echo $row['id']  ?>  </td>
    <td>  <?php echo $row['roll_number']  ?>  </td>

    <td> 
    <input type="radio" name="attendence_status[<?php echo $counter; ?>]" 
    <?php if($row['attendence_status']=="Present")
    echo "checked=checked";
    ?> value="Present">Present 
    <input type="radio" name="attendence_status[<?php echo $counter; ?>]" <?php if($row['attendence_status']=="Absent")
    echo "checked=checked";
    ?> value="Absent">Absent

    </td>
    </tr>
    <?php
    $counter++;
}
    ?>

  

它显示未定义的索引：第一行的日期<?php $result=mysqli_query($con,"SELECT * FROM attendance_records where date='$_POST[date]'");   我在网上找不到任何解决方案，所以也许有人可以帮助我。