There is a table
users with autoincrement primary key
There is also a table
employees (every employee is a user but not vice versa). The
employees primary key is
userid. The field
userid is not autoincrement.
employees.userid should be a foreign key for
Which kind of relationship in Workbench it should be?
As far as I understand:
It cannot be 1:1 relationships because for a given user the corresponding employee may not exist.
It is not advisable to be 1:n relationship because n can be only 0 or 1.
It should be an identifying relation because a user is determined by an employee.
Please advise me what is the best relationship in this case.