UML - Association between 3 classes

Question

I have a piece of statement that I don't understand how to model it in a class diagram. It is about Formula 1 races. The piece is the following:

We can only have one race per circuit in each season

So there is a relationship between CIRCUIT, SEASON and RACE.

---

I believe that it is a ternary association, but a mate told me that it could be an association between CIRCUIT - SEASON and then an association between that association and RACE:

Is that picture wrong? I mean, association should be between 2 classes as far as I know. Not between a class and an association...

Thank's you very much!!!!

EDIT: The statement was wrong, I restated it and could be translated in: (imagine we have 3 circuits)

• Circuit A in Season 1 --> Race 1
• Circuit B in Season 1 --> Race 2
• Circuit C in Season 1 --> Race 3
• Circuit A in Season 1 --> Race 4 (This should not be allowed, we can only have one race per circuit in each season)
• Circuit A in Season 2 --> Race 5 (This is correct)

We can only have 1 race per circuit in each season

Answer 1

To make Race an association class as desired, make the horizontal connector dashed and remove the multiplicities. The above currently shows sort of a ternary connector (see discussion).

This is equivalent to

The multiplicity 0..1 tells that there is one or no race per season and circuit.