登录后，用户需要填写另一张表格。这个网站只有一个表叫做 users 列命名为-

Ten_School_name, Ten_Board, Ten_Percentage, Twl_School_Name, Twl_Board, Twl_Percentage
``` `Ten_School_name` ,  `Twl_School_Name` 设置为 `VARCHAR(70)` 默认值为
NULL `Ten_Board` ,  `Twl_Board` 设置为 `VARCHAR(10)` 默认值为
NULL `Ten_Percentage` ,  `Twl_Percentage` 设置为 `int(3)` 默认值为 `NULL` 这个 `Username` ,  `Email` 以及 `Password` 是另外三个列，当用户在网站上注册时，这些列被占用，而rest被设置为null作为默认值。当我通过填写所有六个字段提交表单时，表单成功提交，但如果任何字段留空，则会显示处理脚本时的错误 `Incorrect integer value: '' for column 'Twl_Percentage' at row 2` 我已经浪费了很多时间寻找解决办法。我希望这里有人能解决我的问题。
这是我的表格-

<label>10th Board</label>
<select name="tenth-board">
    <option name="tenth-board1" value="icse">ICSE</option>
    <option name="tenth-board2" value="cbse">CBSE</option>
    <option name="tenth-board3" value="up-board">UP Board</option>
</select>
<br />
<label>10th Percentage</label>
<input type="number" name="tenth-percent">
<br />

<!--12th Class Details-->
<label>12th School Name</label><input type="text" name="twl-school"><br />

<label>12th Board</label>
<select name="twl-board">
    <option name="twl-board1" value="icse">ISE</option>
    <option name="twl-board2" value="cbse">CBSE</option>
    <option name="twl-board3" value="up-board">UP Board</option>
</select>
<br />
<label>12th Percentage</label>
<input type="number" name="twl-percent">

<input type="submit" name="submita" id="" class="" value="Save" /></form>

下面是我处理数据的php脚本-

if (isset($_POST['submita'])) {

$dbServername = "localhost";
$dbUsername = "root";
$dbPassword = "";
$dbName = "jobin";

$con = mysqli_connect($dbServername, $dbUsername, $dbPassword, $dbName);

if (isset($_SESSION['username'])) {
$user = $_SESSION['username'];
echo $user;
$eml = $_SESSION['cand_email'];
echo $eml;
}

$tenthSchool = mysqli_real_escape_string($con, $_POST['tenth-school']);
$tenthBoard = mysqli_real_escape_string($con, $_POST['tenth-board']);
$tenthPercent = mysqli_real_escape_string($con, $_POST['tenth-percent']);
$twlSchool = mysqli_real_escape_string($con, $_POST['twl-school']);
$twlBoard = mysqli_real_escape_string($con, $_POST['twl-board']);
$twlPercent = mysqli_real_escape_string($con, $_POST['twl-percent']);

$sqlsd = "UPDATE users
SET
Ten_School_Name = '$tenthSchool',
Ten_Board = '$tenthBoard',
Ten_Percentage = '$tenthPercent',
Twl_School_Name = '$twlSchool',
Twl_Board = '$twlBoard',
Twl_Percentage = '$twlPercent'
WHERE
Email = '$eml';";

if(!$con)
{
die('Could not connect: ' . mysqli_connect_error());
}
$resultsd = mysqli_query($con, $sqlsd);

if(!$resultsd)
{
die('Could not update data: ' . mysqli_connect_error());
}
if ($resultsd) {
header("Location: ../candidate-registration.php?sd=success");
}

} else {
echo "nothing";
}