1ST NORMAL fORM

[JamesBowtell]

Can any one normalise this to 1st normal form?

Registration No.
Date purchased
Cost
Number of seats
garage ID
garage name
garage address
service date
service cost

The garage information represents each service the car has had

thanks

[Lil Ms Squirrel]

Just quickly cos my tea is ready....

Three tables

tblCar
Registration No.
Date purchased
Cost
Number of seats

tblGarage
garage ID
garage name
garage address

tblService
garage ID
Registration No.
service date
service cost

Don't forget to lose the spaces in the field names

[JamesBowtell]

to me that looks like 2nd and i think 2nd is the furthest it will normalise as 3rd will be done in 2nd nomal form

i think 1st NF is somthing like this

tblCar:

Registration No.
Date purchased
Cost
Number of seats

tblGarage:

garage ID
garage name
garage address
service date
service cost
Registration No.

i think the rule is remove the repeating groups

and 2nd NF would be

tblCar:

Registration No.
Date purchased
Cost
Number of seats

tblGarage:

garage ID
garage name
garage address
Registration No.

tblService:

service date
service cost
garage ID

please correct me if im wrong

[Lil Ms Squirrel]

Any reason why you only want it normalised to 1NF anyway?

[JamesBowtell]

Because i'm learning the steps to change data from un-normalised data to 1ST 2ND and 3RD Normal Form. Therefore, was the post i corrected any good?

thanks

[Danial]

Originally posted by JamesBowtell
Can any one normalise this to 1st normal form?

Registration No.
Date purchased
Cost
Number of seats
garage ID
garage name
garage address
service date
service cost

The garage information represents each service the car has had

thanks

This is already in First Normal Form.

First normal form requires that you dont have repeating data horizontally e.g have two of same fields (Garage Name twice).

Read this article, it might help you to undrstand more http://dev.mysql.com/tech-resources/...alization.html

[JamesBowtell]

So your saying this is 2nd NF?

tblCar:

Registration No.
Date purchased
Cost
Number of seats

tblGarage:

garage ID
garage name
garage address
service date
service cost
Registration No

[Danial]

Originally posted by JamesBowtell
So your saying this is 2nd NF?

tblCar:

Registration No.
Date purchased
Cost
Number of seats

tblGarage:

garage ID
garage name
garage address
service date
service cost
Registration No

I dont think it is yet if your relation between Car and Garage is Many to Many. You will have data duplication e.g same garage name twice.

Now if in your scenario many to many is not needed and it is a one two many between Garage -> Car (1 Grage services many car, 1 care is Serviced at 1 Garage) then post the GarageID in Car table instead of RegNo in Garage Table

If your scenario is many 2 many relationship(1 car is serviced at many Garage, 1 Garage services many Cars) then you would need to decompose the table and have what they called Bridge Table.

e.g
Car:
Registration No (Primary Key)
Date purchased
Cost
Number of seats

Garage:
garage ID (Primary Key)
garage name
garage address
service date
service cost

Car_Garage:
Registration No
GarageID
(Primary key : Registration No and GarageID)

[JamesBowtell]

So by doing that it would be in 2nf? this is confusing...lol