Why is a relation in Yii treated as a non-existent property?

Question

Yii

Hey!
I have 2 tables:
t_product (CODE[ int ], NAME) - derived class Product
l_order_22_product (CODE, PRODUCT_CODE[ int ], COUNT[ int ]) - LOrder22Product
class In the LOrder22Product class, the links are written:

public function relations()
  {
    return array(
      'product' => array(self::BELONGS_TO, 'Product', 'PRODUCT_CODE'),
      'orders' => array(self::BELONGS_TO, 'Orders', 'ORDER_CODE'),
    );
  }

If somewhere in the code I write:

$mod = LOrder22Product::model()->findByPk(13);
echo $mod->product->NAME;

Falls out:
The property "LOrder22Product.product" is not defined.
Although this is not a property, but a relationship, what could be the reason for the error?

Answer 1

Yii picks up connected models very well if foreign keys are affixed to the corresponding tables. Have you set up foreign keys?