Re: newbie: using id's or total desciption

In message <b8928o$91s$1_at_news.tu-darmstadt.de>, Mirko Koenig <koenig_at_v-i-t.de> writes
>Hi
>
>(english is not my mother tongue)
>
>I'm planing a database for sales managment in a little shop.
>I have a table for all articles and one for all customers.
>Than one for all invoices and one for all sold articles.
>
>The one with the invoices hold every data of a invoice without the
>artciles of the invoice. These articles are saved in the table
>sold_articles with the invoice id.
>
>My question is:
>
>If i save an invoice, should i save only the id of the customer the
>invoice goes to or should i save the customers name and address instead
>of the id?

An invoice is a legal document and once it has been issued it can never be changed. If you only include ID fields in the Invoice table then a change in the related data would distort your invoice records. I would always use the current values and not an ID. Remember to add the selling price and tax to the sold_articles table.

I would also add the total invoice value to the Invoice table. That means that you don't need to use the sold_articles table to calculate your sales revenues.

-- 
Bernard Peek
bap_at_shrdlu.com
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