<table id="myTable" class="display" style="width:100%">
        <thead>
            <tr>
                <th>Name</th>
                <th>Last_name</th>
            </tr>
        </thead>
    </table>

$(document).ready(function(){
$('#myTable').DataTable( {
        "processing": true,
        "serverSide": true,
        "order":[],
        "ajax": {
        "url": '<?= base_url('main/getData');?>',
        "type": "POST",
         "data": { '<?php echo $csrf_token_name; ?>' : '<?php echo $csrf_token_hash; ?>' }
        },
    });
})

public function getData()
    {
     $this->security->get_csrf_token_name();
     $this->security->get_csrf_hash();
        $table = $this->main_model->data();
        if (count($table) > 0)
        {
            foreach ($table as $row)
            {
                $tab = array();
                $tab["name"] = $row->name;
                $tab["last_name"] = $row->last_name;
                $r_tab[] = $tab;
            }
            echo json_encode($r_tab);
        }

$(document).ready(function(){
$('#myTable').DataTable( {
        "processing": true,
        "serverSide": true,
        "order":[],
        "ajax": {
            "url": '<?= base_url('main/getData');?>',
            "type": "POST",
             "data": { '<?php echo $csrf_token_name; ?>' : '<?php echo $csrf_token_hash; ?>' }
        },
            'columns': [
      { "data": "name", "name": "name"},
      { "data": "last_name", "name": "last_name"},
    ]
    });
});

public function getData()
    {
     $data['csrf_token_name'] = $this->security->get_csrf_token_name();
     $data['csrf_token_hash'] = $this->security->get_csrf_hash();

        $table = $this->main_model->data();
        if (count($table) > 0)
        {
            foreach ($table as $row)
            {
                $tab = array();
                $tab["name"] = $row->name;
                $tab["last_name"] = $row->last_name;
                $r_tab[] = $tab;
            }

            $output = array(
                "draw"              => $_POST['draw'],
                "recordsTotal"      =>  200, // modify this
                "recordsFiltered"   => 200, // modify this
                "data"              =>  $r_tab
            );

            echo json_encode($output);
        }