Php 如何使用复选框存储多个数据？我知道你必须让它内爆，但如何？

这是我将数据存储到数据库中的代码：

    <?php
    include_once 'dbh.php';

    $name = mysqli_real_escape_string($conn, $_POST['name']);
    $phonenumber = mysqli_real_escape_string($conn, $_POST['phonenumber']);
    $email = mysqli_real_escape_string($conn, $_POST['email']);
    $childrenamount = mysqli_real_escape_string($conn, $_POST['noc']);
    $childrengrade = mysqli_real_escape_string($conn, $_POST['cg']);
    $wanthomesize = mysqli_real_escape_string($conn, $_POST['homesize']);
    $keywords = mysqli_real_escape_string($conn, $_POST['keywords']);

    $sql = "INSERT INTO clientinfo (client_name, client_phonenumber, client_email, client_children_amount, client_children_grade, client_wanting_homesize, client_keywords)
VALUES ('$name', '$phonenumber', '$email','$childrenamount', '$childrengrade', '$wanthomesize', '$keywords');";
    mysqli_query($conn, $sql);

    header("Location: ../Client_Info_For_Open_House.php?signup=success");

使用逗号（，）内爆

这可能会有帮助
我是否可以像那样开始一条新的线路？还有怎么做？我该怎么做？你能给我看看我是如何复制和编写代码的吗？谢谢我也要把两行代码都放进去吗？
    WHAT GRADE IS YOUR CHILD IN (you can select more than one if you have more than one child):<br>
<input type="checkbox" name="cg[]" value="baby" autocomplete="off">baby<br>
<input type="checkbox" name="cg[]" value="elementary" autocomplete="off">elementary<br>
<input type="checkbox" name="cg[]" value="middle" autocomplete="off">middle<br>
<input type="checkbox" name="cg[]" value="high" autocomplete="off">high<br>
<input type="checkbox" name="cg[]" value="college" autocomplete="off">college<br>

implode(',',$_POST['cg']) 

implode(',',$childrengrade)