How can I get the user primary data to his/her panel after he logged in

Question

I am using CodeIgniter 3, in which when after user login his/her data(aadhaar number) not fetching in his panel, (his aadhaar number used for for further operations in his panel). for example when ordering something from his panel where along with order details his aadhaar number also inserting dynamically.

here is the my controller:

public function addToCart(){
    $this->load->library('session');
    $this->Customer_model->addToCart();
}

here is the my model :

public function addToCart(){
    if($this->input->post('bag_size')){
        $checkCart = $this->db->where('customer_aadhaar',$this->session->userdata('cust_aadhaar'))->where('sapling_id',$this->input->post('sapling_id'))->where('bag_id',$this->input->post('bag_size'))->get('customer_cart');
        if($checkCart->num_rows() == 0){

            $pricePerUnit = 5;
            $bagPricePerUnit = $this->db->where('bag_id',$this->input->post('bag_size'))->get('bag_size');

            if($bagPricePerUnit->num_rows() > 0){
                $pricePerUnit = $bagPricePerUnit->row()->price;
            }

            $data = array(
                'customer_aadhaar' => $this->session->userdata('cust_aadhaar'),
                'nursery_id' =>$this->input->post('nursery_id'),
                'sapling_id' => $this->input->post('sapling_id'),
                'bag_id' => $this->input->post('bag_size'),
                'quantity' => 1,
                'price_per_unit' => $pricePerUnit,
                'date' => date('Y-m-d H:i:s')
            );
            if($this->db->insert('customer_cart',$data)){
                $this->session->set_flashdata('added','Added sapling to cart');
                redirect('saplings-list/'.$this->input->post('variety_id').'/'.$this->input->post('nursery_id'));
            }
        }else{
            $this->session->set_flashdata('already','Already Added');
            redirect('saplings-list/'.$this->input->post('variety_id').'/'.$this->input->post('nursery_id'));
        }
    }
}

public function getMyCart(){
    return $this->db->select('customer_cart.*,bag_size.bag_id,bag_size.bagsize,bag_size.price,saplings.sapling')->where('customer_cart.customer_aadhaar',$this->session->userdata('cust_aadhaar'))->join('saplings','saplings.saplingid = customer_cart.sapling_id')->join('bag_size','bag_size.bag_id = customer_cart.bag_id')->get('customer_cart')->result();
}

here is my view :

<form action="<?php echo base_url('add-to-cart')?>" method="post">
    <?php echo $this->session->userdata('cust_aadhaar')?>
    <input type="text" name="cust_aadhaar" value="<?php echo $this->session->userdata('cust_aadhaar')?>">
    <input type="text" name="sapling_id" value="<?php echo $eachSapling->sapling_id?>">
    <input type="text" name="variety_id" value="<?php echo $this->uri->segment(2);?>">
     <input type="text" name="nursery_id" value="<?php echo $this->uri->segment(3);?>">
    <div class="d-md-flex">

        <div class="content px-md-3 my-3 my-md-0"> 
            <span class="mb-0 font-w-600 h5"><?php echo $eachSapling->sapling?></span>
            <hr>
            <select required class="form-control" name="bag_size">
                <?php foreach($availableBags as $eachBags){?>
                    <option value="<?php echo $eachBags->bag_id?>"><?php echo $eachBags->bagsize?> (<?php echo $eachBags->price?>)</option>
                <?php }?>
            </select>
        </div>
        <div class="my-auto">
            <button type="submit" class="btn btn-outline-primary font-w-600 my-auto text-nowrap"><?php if($this->session->userdata('lang')=='EN') { ?>
           Purchase
        <?php } else {?>
     ಖರೀದಿ
     <?php }?></button>
        </div>

    </div>
</form>