Draw Entity Relationship Diagram (ERD) with entities,
attributes task(function) inclusive primary key, foreign key &
cardinality using Chen Notation.
1. The KK Furniture company sells a number of different
furniture products.
- These products are grouped into several product lines.
- The identifier for a product is Product_ID, while the
identifier for a product line is Product_Line_ID.
- Referring to the customer invoice, we identify the following
additional attributes for product: Product_Description,
Product_Finish, and Unit_Price.
- Another attribute for product line is Product_Line_Name.
- A product line may group any number of products, but must group
at least one product.
- Each product must belong to exactly one product line.
2. Customers submit orders for products The identifier for an
order is Order-ID, and another attribute is Order_Date.
- A customer may submit any number of orders, but need not submit
any orders.
- Each order is submitted by exactly one customer.
- The identifier for a customer is Customer_ID.
- Other attributes include Customer_Name and
Customer_Address.
3. A given customer order must request at least one product.
- Any product sold by KK Furniture may not be requested on any
order, or may be requested on one or more orders.
- An attribute associated with each order and product is
Quantity, which is the number of units requested.
4. KK Furniture has established sales territories for its
customers.
- Each customer does business in one or more of these sales
territories.
- The identifier for a sales territory is Territory_ID.
- A sales territory may have any number of customers, or may not
have any customers doing business.
5. KK Furniture Company has several salespersons. The identifier
for a salesperson is Salesperson_ID.
- Other attributes include Salesperson_Name,
Salesperson_Telephone, and Salesperson_Fax.
- A salesperson serves exactly one sales territory.
- Each sales territory is served by one or more
salespersons.
6. Each product is assembled from one or more raw materials.
- The identifier for the raw material entity is Material_ID.
- Other attributes include Unit_of_Measure and Unit_Price.
- Each raw material may be assembled into one or more
products.
7. Raw materials are supplied by vendors.
- The identifier for a vendor is Vendor_ID.
- Other attributes include Vendor_Name and Vendor_Address.
- Each raw material can be supplied by one or more vendors.
- A vendor may supply any number of raw materials, or may not
supply any raw materials to KK Furniture.
- An attribute of the relationship between vendor and raw
material is Unit_Price
8. KK Furniture has established a number of work centers.
- The identifier for a work center is Work_Center_ID.
- Another attribute is Location. Each product is produced in one
or more work centers.
- A work center may be used to produce any number of products, or
may not be used to produce any products.
9. The company has over 100 employees.
- The identifier for employee is Employee_ID.
- Other attributes are Employee_Name, EmployeeAddress, and
Skill.
- An employee may have more than one skill.
- A skill can be mastered by many employees
10. Each employee works in one or more work centers.
- A work center must have at least one employee working in that
center, but may have any number of employees.
11. Each employee has exactly one supervisor.
- An employee who is a supervisor may supervise any number of
employees, but not all employees are supervisors.
Subject: Database system
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