While studying 3FN, I came across 2 interesting examples and wondered if by making a small change, the examples would continue to serve 3FN.

Explanation about the 3FN concept

Explaining the Context

Below is an illustration presented by the book to exemplify the standardization of a scheme that meets 3FN. Look at the example below and compare it to the change.

Book Example

Please note that as it is illustrated, an employee can only work in one department, not several, and each department can be made up of several employees.

My Example

I would like to know if in case the Dnumero attribute in the DF1 table was primary key, would the scheme continue to respect 3FN?

  

Business rule : Um funcionário pode trabalhar em mais de um departamento e em cada departamento existe mais de um funcionário.

     

    

This small change to the Dnumero key is required because an employee can work across multiple departments, and each department can be made up of multiple employees.

  

Note that one of the employees can be the department manager, each department has a manager who is also an employee.

Final remarks

How do you set the example to respect 3FN and the business rule at the same time?