Model Relation Has_One With Or In On Clause

Yii 1.1 General Discussion
1

I need create the condition that "ON" clause has an "OR", thus: (FIELD_X = FIELD_Y OR FIELD_A = FIELD_N)

How to create a relation in these conditions?

The current relation:

‘product’ => array(self::HAS_ONE, ‘Product’, array(‘FIELD_X’ => ‘FIELD_Y’)),