There is an organization database. It has tables, Отделы , Подотделы and Сотрудники .

In the Подотделы table, there is a foreign key for the department to which it belongs.

Do I understand correctly that the database corresponds to 3NF, in the Сотрудники table there should be a foreign key only in the subdivision to which the employee belongs?

If, on the other hand, Сотрудники have fields with foreign keys for a department and a subdivision, then this will no longer be 3NF, since the subdivision depends on the department?

1 answer 1

For the design of the database there are special standards, such as IDEF1X .

Following this standard, many questions disappear by themselves, and at the output you get 3NF.

To follow this standard, there is even a special software, such as Toad Data Modeler.