如何显示另一个表（codeigniter）的内容？

I want to do crud on my page and I have to get content from another table and display it in a select tag. my plan was to make an update page wherein it will get the data from another table to display (in this case the category_name, cat_id was the foreign key at the menu table).

I already tried to join because that's what other forums have said but I think I was wrong.

help would really be appreciated.

this is my model:

function inputMenuToUpdate($menu_id){
        $this->db->select('cat_id, category.category_id, category.category_name AS category_name');
        $this->db->from('menu');
        $this->db->join('category', 'menu.cat_id = category.category_id');
        $this->db->where('menu_id',$menu_id);

        return $query->row();
        }

this is my controller:

public function inputToUpdate($menu_id){

        $data['row'] = $this->adminMenuModel->inputMenuToUpdate($menu_id);
        $this->load->view('adminEdit', $data);

    }

this is my view:

 <tbody>
                    <!-- $result is from the $data in CrudController-->
                    <?php foreach($result as $row){?>
                    <tr>
                        <td><?php echo $row->menu_name; ?></td>
                        <td><?php echo $row->category_name; ?></td>
                        <td><?php echo $row->price; ?></td>
                        <td><?php echo $row->description; ?> </td>
                        <td>

                            <a href="<?php echo site_url('adminMenuController/inputToUpdate');?>/<?php echo $row->category_id; ?>"> <i class="fa fa-pencil"></i> </a>
                        </td>
                    </tr>
                    <?php } ?>
                </tbody>

and this is my update page:

<div class="container" style="width: 40rem;">
            <form method="POST" action="<?php echo site_url('adminMenuController/update'); ?> / <?php echo $row->category_id; ?>">
                <button type="button" class="btn btn-link"> <a href="#"> Go Back </a> </button>

                <h1> UPDATE MENU </h1>
                <div class="border-bottom"></div>

                <br>
                <br>
                <label for="upMName">New Drink Name</label>
                <input type="text" name="mn" class="form-control" id="upMName" value="<?php echo $row->menu_name ?>"></input>

<!--                <label for="cat"> Category </label>
                <select id="cat" class="form-control">
                    <option> <?php echo $row->category_name; ?> </option>
                </select> -->

                <label for="upPrice">New Price</label>
                <input type="number" name="price" class="form-control" id="upPrice" value="<?php echo $row->price ?>"> </input> 

                <label for="updesc">New Description </label>
                <input type="text" name="desc" class="form-control" id="updesc" value="<?php echo $row->description ?>"> </input> 

                <br> 
                <button type="submit" class="btn btn-info"> Update </button> 
                <button type="reset" class="btn btn-danger"> Cancel </button>
            </form>
        </div>