department_id: INT to hold reference to department role belongs to
Employee
id: INT PRIMARY KEY
first_name: VARCHAR(30) to hold employee first name
last_name: VARCHAR(30) to hold employee last name
role_id: INT to hold reference to employee role
manager_id: INT to hold reference to another employee that is manager of the current employee. This field might be null if the employee has no manager.
schema should contain the following three tables:
Department
id: INT PRIMARY KEY
name: VARCHAR(30) to hold department name
Role
id: INT PRIMARY KEY
title: VARCHAR(30) to hold role title
salary: DECIMAL to hold role salary
department_id: INT to hold reference to department role belongs to
Employee
id: INT PRIMARY KEY
first_name: VARCHAR(30) to hold employee first name
last_name: VARCHAR(30) to hold employee last name
role_id: INT to hold reference to employee role
manager_id: INT to hold reference to another employee that is manager of the current employee. This field might be null if the employee has no manager.