I have a problem statement (briefed),
Database for a Fitness Club -
Client's Attributes: Name, Address, Ph. No.
Membership Plan's Attributes: Beg. date, Sub. Fee, Monthly Fee, Duration
Trainer's Attributes: ID, Name, Salary
Relationship-Types: Client is 'Enrolled In' a Mem. Plan, and Client 'Meets' Trainers
Enrolled In: Client has total participation while Mem. Plan does not.
Meets: Client & Trainer, both have total participation.
By Meets, it means, a Client entity attends a session guided by a Trainer entity.
So, Client & Mem. Plan are weak entity types & Trainer is a strong entity type.
When converted to an ER diagram, Client & Mem. Plan are related to each other, and Client is related to Trainer.
Is it a possible to have such an ER diagram or is there another way to rectify the same?
Edit: This ER diagram represents what I think it should be (without partial keys) and consider arrows in diagram as straight lines connecting two blocks/shapes.
Feel free to correct me if I'm wrong anywhere.
I also have an entity 'Workout Session', which has a relation with Trainer. A Workout Session is conducted by one Trainer only, but the problem states to keep data of only Trainers which a Client meets, not the Sessions he/she attends. But since that wasn't related to the question I needed to ask, so I didn't add that part.
I think there is no single attribute of either Client or Membership Plan which I can use to distinguish their respective entities uniquely, so I think Client and Membership Plan are weak entity types.
I have provided as much details as I can as I can't disclose the complete statement due some reasons.