Hi, 

I'm trying to get the id's of the invoices that don't have payments. 

I've try like this: 

invoice_ids = invoice_obj.search(self.cr, self.uid, [('payment_ids','!=',[])])

And I get this WARNING/ERROR:

2014-05-20 08:17:54,280 10010 WARNING db openerp.osv.expression: The domain term '('payment_ids', '!=', [])' should use the 'in' or 'not in' operator.
2014-05-20 08:17:54,280 10010 ERROR db openerp.osv.expression: The field 'Payments' (payment_ids) can not be searched: non-stored function field without fnct_search

And it returns all of the invoices. 

If I try like this: invoice_ids = invoice_obj.search(self.cr, self.uid, [('payment_ids','!=',False)]) the warning disapears but the error is the same and it returns all of the invoices.

So, how do I get the invoices that have been paid and partially paid ? 

Thanks.