I use fnDrawCallback to present a column with ajax data.
But in this column search is not working. (In other column which data from php is workable).
I also create the column by php first with null data.

(This is my script)

$('#example').DataTable({
       "order": [[ 0, "desc" ]],
       // detect page changed
        "fnDrawCallback": function( oSettings ) {
           for(var $i=0;$i<obj.length;$i++){
              ajax_to_find_outline(obj[$i]);
           }
          }
});

This is my function to get data by ajax.

function ajax_to_find_outline($order_id){
        $.ajax({
            url: '<?php echo base_url(); ?>index.php/ajax-find-outline', 
            type: 'POST',
            data: { 
                order_id: $order_id
            },
            error: function(jqXHR,status, errorThrown){
                console.log(errorThrown);
                console.log(jqXHR.responseText);
                console.log(jqXHR.status);
            },
            success: function(data) {
                var td = document.getElementById("td-"+$order_id); // return from ajax
                if(td==null){  // the order_id data not on this page
                    // do nothing
                } else {
                    td.innerHTML = data;
                }
            }
        });
}