Urgent Normalisation help!!!

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Urgent Normalisation help!!!

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Gail Shaw SSC Guru Points: 1004504 More actions · Answer 1

Aty01 (3/27/2012)
orders belong to a customer

Which you already have handled since the Orders table has a foreign key to customers.

Right, next thing... Look at these two entities

Order

Order Date

product description

price

qty ordered

Reference to Customer Table

----------------------

Stock

Stock Description

Price

Qty in Stock

Reference to Supplier table

What's wrong there? I'll give you a hint, where did the product description in the Orders table come from? I'm sure the customer doesn't type in what he wants to buy.

Gail Shaw
Microsoft Certified Master: SQL Server, MVP, M.Sc (Comp Sci)
SQL In The Wild: Discussions on DB performance with occasional diversions into recoverability

We walk in the dark places no others will enter
We stand on the bridge and no one may pass

Gail Shaw SSC Guru Points: 1004504 More actions · Answer 2

Lynn Pettis (3/27/2012)
GilaMonster (3/27/2012)
Lynn Pettis (3/27/2012)
Aty01 (3/27/2012)
there is no link to order table
Stepping in a minute. Look at your Order table and think of an order you may have placed with a company. How many items can one customer order at one time? How many times do you see the customer information on that order?
Getting there....
I know, but you started looking at Orders, so thought it was a good time to expand thoughts around that one item.

Just don't want to confuse him.

Gail Shaw
Microsoft Certified Master: SQL Server, MVP, M.Sc (Comp Sci)
SQL In The Wild: Discussions on DB performance with occasional diversions into recoverability

We walk in the dark places no others will enter
We stand on the bridge and no one may pass

Aty01 SSC Veteran Points: 244 More actions · Answer 3

Aty01

SSC Veteran

Points: 244

March 27, 2012 at 11:39 am

#1465214

one order has many stock

-----------

Stock ID

Lynn Pettis SSC Guru Points: 442467 More actions · Answer 4

Aty01 (3/27/2012)
one order has many stock
-----------
Stock ID

Right. What else?

Lynn Pettis SSC Guru Points: 442467 More actions · Answer 5

GilaMonster (3/27/2012)
Lynn Pettis (3/27/2012)
GilaMonster (3/27/2012)
Lynn Pettis (3/27/2012)
Aty01 (3/27/2012)
there is no link to order table
Stepping in a minute. Look at your Order table and think of an order you may have placed with a company. How many items can one customer order at one time? How many times do you see the customer information on that order?
Getting there....
I know, but you started looking at Orders, so thought it was a good time to expand thoughts around that one item.
Just don't want to confuse him.

I don't think we are. Looks like he is thinking things through bit by bit.

Aty01 SSC Veteran Points: 244 More actions · Answer 6

Aty01

SSC Veteran

Points: 244

March 27, 2012 at 11:47 am

#1465227

what else am i suppose to look for

Lynn Pettis SSC Guru Points: 442467 More actions · Answer 7

Aty01 (3/27/2012)
what else am i suppose to look for

Think about orders you have placed with a company. Right now I am just trying to help you look at one piece of the data you are going to be storing.

Aty01 SSC Veteran Points: 244 More actions · Answer 8

Lynn Pettis (3/27/2012)
Aty01 (3/27/2012)
what else am i suppose to look for
Think about orders you have placed with a company. Right now I am just trying to help you look at one piece of the data you are going to be storing.

customer details

Lynn Pettis SSC Guru Points: 442467 More actions · Answer 9

Aty01 (3/27/2012)
Lynn Pettis (3/27/2012)
Aty01 (3/27/2012)
what else am i suppose to look for
Think about orders you have placed with a company. Right now I am just trying to help you look at one piece of the data you are going to be storing.
customer details

What makes up the customer details? Is this information stored any where else?

Aty01 SSC Veteran Points: 244 More actions · Answer 10

What makes up the customer details? Is this information stored any where else?

Customer

Customer Forename

Customer Surname

Street

Town

Postcode

Email

Category

and the order table will have this detail, so that they can dispach it to the right customer

Lynn Pettis SSC Guru Points: 442467 More actions · Answer 11

Aty01 (3/27/2012)
What makes up the customer details? Is this information stored any where else?
Customer
Customer Forename
Customer Surname
Street
Town
Postcode
Email
Category
and the order table will have this detail, so that they can dispach it to the right customer

Second question I had asked, where else is this information stored? Do you need to store it with the order? Why or why not?

Please answer these questions before continuing. It will make a good discussion about normalization.

Aty01 SSC Veteran Points: 244 More actions · Answer 12

you need to store it with order so that they know whos order it is

Lynn Pettis SSC Guru Points: 442467 More actions · Answer 13

Aty01 (3/27/2012)
you need to store it with order so that they know whos order it is

Not necessarily. This information is also stored in the customer table, correct?

Aty01 SSC Veteran Points: 244 More actions · Answer 14

Aty01

SSC Veteran

Points: 244

March 27, 2012 at 12:15 pm

#1465270

so whatam i looking for

Lynn Pettis SSC Guru Points: 442467 More actions · Answer 15

Aty01 (3/27/2012)
so whatam i looking for

How are you going to related the customer table to the orders?

Now to discuss normalization. If you store customer information in both the order table and the customer table, what level of normalization are you looking at?