Username & Password Database Design

Question

I\'m Designing a database for industrial company , I Have these entities ( Employee , Suppliers , Customers , Drivers ) and Each one of them has his own unique ID ( Employee Id

Answer 1

Create an entity table. Whenever you add an entry to the other tables ( Employee , Suppliers , Customers , Drivers ), add a row in the entity table for them.

In the other tables ( Employee , Suppliers , Customers , Drivers ), add a foreign key (column name: entity_id).

To get the entity id for an employee:

SELECT entity_id FROM employees WHERE id = {employee_id};

As a bonus, fields that are common to all entity types can be moved to the entity table.