normalisation

5 steps for normalisation:

1) List the un-normalised data and identify repeating groups (in brackets).
2) Choose a key for the main group.
3) Extract the repeating group and give that a key.
4) Identify and extract partial key dependencies.
5) Identify and extract non key dependencies.

For the 0NF i am going to list the un-normalised data.

0NF:

Order

Customer No
Name
Address
Date
Salesman No
Salesman Name
(Item No)
(Description)
(Quantity)
(Price)

Order Value

1NF:

Order

Customer No
Date
Name
Address
Salesman No
Salesman Name
Order Value

Order Item

Customer No
Date
Item No
Description
Quality
Price


2NF:

Order

Customer No
Date
Salesman No
Salesman Name
Order Value

Customer

Customer No
Name
Address

Order item

Customer No
Date
Item No
Quantity

Item

Item No
Description
Price

3NF:

Order

Customer No
Date
Salesman No
Order Value

Salesman

Salesman No
Salesman name

Customer

Customer No
Name
Address



Item

Customer No
Date
Item No
Quantity
Item No
Description
Price