Automatic input category name when id categories included

I have a problem ... I have two tables, products and categories. product: id, nm_product, id_category, nm_category category: id_category, nm_category

I want to enter category.id_category to product.id_category and category.nm_category to product.category.

My question, How do nm_category input automatically when id_kategori already loaded?

<select type="text" class="form-control" name="id_category">
                        <option>Kategori</option>
              @foreach($category as $kategori)
                        <option value=""></option>
              @endforeach
        </select>

via Chebli Mohamed