How to join three tables ?

[John Zoetebier]

I have three tables linked like this:
client -> invoice -> payment

Joining client to invoice works fine.
Joining payment giver error:
=>
No foreign key between table client and table payment !
=>

How can I join these three tables ?

[John Zoetebier]

I have figured this out.
Query.join returns Join that can be used to join other tables.