I have a doubt with a statement to pass to the UML and doubts with the ternary relations due to how it is expressed, it says like this:
It may happen that some athlete is federated. In fact, an athlete may be associated with none, one or several sports federations. For each federation to which he is associated, you want to store the federative license number in the database. It is also possible that there are federated clubs, in which case, you also want to know the corresponding federation. It is known that federations for which there is no federated athlete will not be stored in the database, although federations without any federated club can be registered.
What I did was this but I have doubts that it is a ternary relationship between the federation, athletes and club:
I think I could put a ternary here but I have doubts about his relationships, no matter how many I give him, I don't see it clearly.
I just don't see the ternary relationship. On one side go the athletes and on the other the clubs. In fact, at no time do you mention any relationship between athletes and clubs. What I see missing from your schema are the tables that represent the relationships
asocian
, since they have N:N cardinality, you can't omit them. When in doubt, try to record a fictitious data. It is the best way to see if it is stored correctly or not.