如何将SELECT ALL值或SELECTED复选框值插入mysql中的不同列？

I want to Insert SELECT ALL values or SELECTED values into different columns in MySQL. On choosing SELECT ALL, all the values are inserting correctly in sql but on selecting some checkboxes data is not inserting in SQL data.

Jquery

<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.2.1/jquery.min.js"></script>
<script>
$(document).ready(function() {

$("#select_all").change(function(){
    var status = this.checked;
    $('.checkbox').each(function(){
        this.checked = status;
    });
});

$('.checkbox').change(function(){
    if(this.checked == false){
        $("#select_all")[0].checked = false;
}

if ($('.checkbox:checked').length == $('.checkbox').length ){ 
        $("#select_all")[0].checked = true;
}
});
});
</script>

PHP

<?php
$addbook=$_POST['addbook'];
$memdet=$_POST['memdet'];
$vbookd=$_POST['vbookd'];
$modify=$_POST['modify'];
$result=mysqli_query($db,"insert into apanel(addbook,memdet,vbookd,modify)values('$addbook','$memdet','$vbookd','$modify')");
?>

HTML

<input type="checkbox" id="select_all"/> Selecct All<br>
<input class="checkbox" type="checkbox" value="1" name="addbook" />Add Book<br>
<input class="checkbox" type="checkbox" value="1" name="memdet" />View Member Details<br>
<input class="checkbox" type="checkbox" value="1" name="vbookd" />View Book Details<br>
<input class="checkbox" type="checkbox" value="1" name="modify" />Edit/Delete<br>

I want to insert selective checkboxes also in MYSQL database. Help required

Before inserting into mysql check if the value is exist in $_POST['addbook'] do this for all the checkboxes. You can also use array of checkbox.

     <?php
       // Do this for rest of the values also.

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

               $addbook=$_POST['addbook'];

            }else{

               $addbook = "default value"

            }
    ?>