Mahmoud,
>Are these values atomical?
>My other question is what are the repercussions of
>not putting a table in 2nd and 3rd Normal Form.
Your 'choice1-subchoice1' etc are combined values, so they aren't
atomic. From your three example dropdown values, it looks as if 'choice'
and 'subchoice' have a many-to-many relationship, and if that's so,
you'll probably need a second table for 'subchoice' and a third table to
store combinations of choice and subschoice.
There are examples of disadvantages of not putting a table in 2NF or
3NF at http://www.artfulsoftware.com/mysqlbook/sampler/mysqled1ch01.pdf,
click on 'Normalisation and the normal forms', & read the sections on
1NF, 2NF and 3NF.
PB
-----
Mahmoud Badreddine wrote:
>Hello,
>I have two questions:
>I would like to know whether I am violating the principle of atomicity in
>doing the following:
>
>I have a form which has a field with the following options: Choice1, choice2
>and choice3.
>Each of the above choices have two further subchoices : subChoice1,
>subchoice2.
>
>so in my form I have a pull-down list and these are the choices I have:
>choice1-subchoice1
>choice1-subchoice2
>choice2-subchoice1
>....
>....
>and so on.
>
>Are these values atomical?
>
>My other question is what are the repercussions of not putting a table in
>2nd and 3rd Normal Form.
>Thank you.
>
>
>
>
>------------------------------------------------------------------------
>
>No virus found in this incoming message.
>Checked by AVG Anti-Virus.
>Version: 7.0.308 / Virus Database: 266.9.10 - Release Date: 4/14/2005
>
>
Attachment: [text/html]
No virus found in this outgoing message.
Checked by AVG Anti-Virus.
Version: 7.0.308 / Virus Database: 266.9.10 - Release Date: 4/14/2005
