Given the following business scenario, create a Crow’s Foot ERD using a specialization hierarchy if appropriate. Granite Sales Company keeps information on employees
and the departments in which they work. For each department, the department
name, internal mail box number, and office phone extension are kept. A department
can have many assigned employees, and each employee is assigned to only one
department. Employees can be salaried, hourly, or work on contract. All employees
are assigned an employee number, which is kept along with the employee’s name
and address. For hourly employees, hourly wages and target weekly work hours are
stored; for example, the company may target 40 hours/week for some employees,
32 for others, and 20 for others. Some salaried employees are salespeople who can
earn a commission in addition to their base salary. For all salaried employees, the
yearly salary amount is recorded in the system. For salespeople, their commission
percentage on sales and commission percentage on profit are stored in the system.
For example, John is a salesperson with a base salary of $50,000 per year plus a
2 percent commission on the sales price for all sales he makes, plus another 5 percent
of the profit on each of those sales. For contract employees, the beginning date and
end date of their contracts are stored along with the billing rate for their hours.