MER - Entity and relationship model

Question

I wonder if my MER is correct and if it is possible to make a relationship N:N between animals and schedules.

Specifications I created for the system:

Computerize the scheduling of a bath and Osa, involving customers, attendants, animals, scheduling, scheduling, services.

• The system will allow the customer to register in the system;
• The system will allow the customer to register their animals in the system;
• The system will allow the customer to choose which attendant he will do the service;
• The system will allow the client to make scheduling requests;
• The system will allow the attendant to approve or cancel requests;
• The system will allow the attendant to register new services;
• The system will allow the customer to make the scheduling request by searching for the animal at home;
• The system will allow parameterize the availability time of the attendant;
• The system will allow parametrize the availability time of the bath and Tosa;

Answer 1

This depends a lot on the information flow/business rules of your application. For example, if needed more than one address, there could be separate address and client table. In general (with exceptions), all repeating information must have a specific table and be "looped" with a referent ID.

For an N:N relationship for animals and schedules, perhaps the inclusion of a table with the columns ID - ID_ANIMAL - ID_AGENDAMENTO would solve your problem.

I recommend that there be a history of services for animals and the possibility of registering more than one service for a given animal.