1. Introduction

This is a simple netshop where customers can buy products.

2. Actions

• N1: We are able to add products
• N2: Every product has a name and price
• N3: Customer can check the name and price of the products
• N4: Customer can check how many pieces of particular product is on the store
• N5: We are able to check: who has ordered, what product and when
• N6: At this stage we are satisfied, if the customer can order only one procuct-type at a time. This means that the customer can choose a product and then how many pieces, but the customer can not include another product to the same order.
• N7: We need to know the address of the Customers, so that we can send the products to them
• I1: We need to know the email-address of our customers
• D1: We would like to know how old our customers are

3. Connections

We have already made the payment system, so you don't have to take care of that.

4. Other features

We would like that the shop is open 24 hour.

In above example "N" means that the feature is necessary, "I" means that it is important(but not mandatory) and "D" means desirable (it would be nice to have).

NF1

There is no similar fields in any tables. And all the fields are divided into pieces. So the database is in NF1

NF2

Customerss and Products has a primary key which consist of one field, so they are in NF2. In Orders-table Date and Amount are not dependent on Customers_ID or Products_Id, so the databse is in NF2.

NF3

In Customers table City is dependent on postalcode, even postalcode is not the primary key. So the database is not in NF3. And this should be fixed!

Field definitions for NetShop tables might be something like this:

Customers-table
Field	Data Type	Qualifications
id_customers	INT	primary key, values between 0 and 9999
firstname	VARCHAR(15)	mandatory, maximum length 15 characters
lastname	VARCHAR(15)	mandatory, maximum length 15 characters
streetaddress	VARCHAR(45)	mandatory, maximum length 45 characters
postalcode	CHAR(5)	mandatory, length 5 characters
city	VARCHAR(20)	mandatory, maximum lenth 20 characters
email	VARCHAR(50)	mandatory, maximum length 50 characters

Products-table
Field	Data Type	Qualifications
id_products	INT	primary key, values between 0 and 9999
name	VARCHAR(15)	mandatory, maximum length 15 characters
price	DOUBLE	mandatory, values between 0 and 100 000
amount	INT	mandatory, values between 0 and 10 000

Orders-table
Field	Data Type	Qualifications
id_customers	INT	primary key, values between 0 and 9999, foreign key which references to table Customers
id_products	INT	primary key, values between 0 and 9999, foreign key which references to table Products
date	Date	mandatory, time has to include seconds,... and year
amount	INT	mandatory, values between 0 and 10 000

• We are not allowed to delete customer, if that customer has orders
• If we have to change Customers_Id, we will cascade the changes to Orders
• We not allowed to delete product, if that product has orders
• If we have to change Products_Id, we will cascade the changes to Orders