Bank query problem with Codeigniter

I have a table in the database (use_shopBlock), which blocks a button in the view, but when I give a <?php var_dump($shopBlock);?> the result is NULL .

My view:

<?php
             $shopBlock = $this->main_model->configBlock('use_shopBlock');

                  if($shopBlock == 9){
                     echo '
                        <button type="button" id="open-shop" class="btn btn-primary"><i class="fa fa-shopping-cart" aria-hidden="true"></i>Abrir Minha Loja</button>
                     ';
                  }
               ?>

My model:

 public function configBlock($column = false) {
        $this->db->limit(1);

        if ($column) {
            $this->db->select($column);
        }

        $query = $this->db->get('users');
        $query = $query->result();

        if ($query) {
            if ($column) {
                return $query[0]->$column;
            } else {
                return $query[0];
            }
        } else {
            return false;
        }
    }

I will attach how my table was made in MYSQL

Whentheusersignsup,headdsthevalue8intheshopBlocktable,andintheadministrator,whenchangedto"Store Released", changes to 9.

This value 9 should release the button in the view.

Code that changes value in admin:

<div class="form-group">
                        <label>Ativar loja</label><br>
                            <select class="form-control" name="shopBlock">
                            <option <?=(($e && $item->use_shopBlock == '9') ? 'selected' : '')?> value="9">Loja Liberada</option>
                            <option <?=(($e && $item->use_shopBlock == '8') ? 'selected' : '')?> value="8">Loja Bloqueada</option>
                        </select>
                    </div