| Re: Mr. Stuckle and Mr. Miller - explain normalisation with an example [message #185277 is a reply to message #185275] |
Sun, 16 March 2014 20:54   |
Luuk
Messages: 329
Registered: September 2010
Karma:
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Senior Member |
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On 16-3-2014 21:22, richard wrote:
> I'll bet you won't.
>
> The table I have now consists of the following columns.
> songid,hits, title, author, license.
> Please explain how this data should be normalised.
> And why.
> Thank you.
>
The column 'author' should be an 'authorId'.
why?
- Because 1 author can write more than 1 song
- An author has properties to, like i.e.:
- birtdate
- date of death (if applicable)
- city of birth
- etc
- etc
Another advantage of this is that, when you found out that you
misspelled the name of this author, you only need to change 1 record to
correct the songs of this author.
Another example of this might be 'license'
If i ask questions like:
When became this license valid?
And 'until when was this a valid license'?
Did the author have more than 1 license?
You might say "this is not applicable to my application"
But, in real life, one should be prepared that this will become
applicable for your application. (Because users only start to think
after they see the portential of your application)
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