1. Order Database – ER Diagram
Prepared by
Taylor Segrave
Spring 2017

2. Designing Databases with Entity Relationship Diagrams
Step 1: Define Entity Classes and Primary Keys
Step 2: Define Relationships Among Entity Classes
Step 3: Define Attributes for each Table
Step 4: Create Database

3. Step 1: Define Entity Classes and Primary Keys
CUSTOMER
CustomerID
ORDER
OrderID
PRODUCT
ProductID
ORDERITEM
ProductID;OrderID
There is not a limit to the number of orders a customer may place. Each customer can have one order, multiple orders, or be in your database without any orders. Each order is made by a single customer. Orders must have at least one product. Orders may have multiple products. The same product could be sold through many orders. Products can be listed in the database but not ordered by a customer.
Business Rules
1. Customer can have multiple orders.
2. Customer may have no orders.
3. Each order must have one Customer.
4. Each order must have a Customer.
5. An Order must have one Product.
6. An Order may have multiple Products.
7. A Product may have multiple orders.
8. A Product may have no orders.

4. Step 2: Define Relationships Among Entity Classes
CUSTOMER
ORDER
PRODUCT

5. Step 3: Define Attributes for each Table
CUSTOMER
CustomerID
LastName
FirstName
address
Location
Gender
Major
PhoneNumber
ORDER
OrderID
[CustomerID]
OrderDate
Quantity
Price
ProductID
PRODUCT
ProductID
Description
OrderID
ORDERITEM
OrderID
ProductID

6. Step 3: Define Attributes for each Table
CUSTOMER
CustomerID
FirstName
LastName
Address
Major
Location
Gender
ORDER
OrderID
[CustomerID]
OrderDate
PRODUCT
ProductID
ProductName
Price
BatchSize
Description
Type
ORDERITEM
OrderID
ProductID
Quantity

7. (DBMS system - Microsoft Access)
Step 4: Create Database
(DBMS system - Microsoft Access)