How to add a column to the sql insert server side?

The record is inserting just fine… but the c_id (customer id) field, which is not shown to the customer in either the form or the DataTable, is not present. I wish to add it to the sql insert.

I'm currently passing the value via the url as such:

$(document).ready(function() {
    editor = new $.fn.dataTable.Editor( {
        ajax: "workorder.php?c_id=1,

I could use the session to do this as well, but for testing I was attempting to use _POST.

Now I wish to include c_id in the insert… this is where I get lost.

I tried writing to _POST['c_id']=1, which remains null regardless.

What method is used to add to the sql insert?

I'm not sure if this is the best method for adding variables to the insert… but I know it will work, once I know how to write to the sql insert statement.