Subject Re: [firebird-support] Invoice Detail: Design / Normalization
Author Hannes Streicher
Guten Tag shg_sistemas@... [firebird-support],

i do it that way, store all information in the Invoice,
because my experience is Data changes
changing your Item Description would change your Invoice which would get you in trouble with Tax Authorities
as an alternative you could "Version" your description and link to the correct Version

> It's a design / normalization question: How to save Invoice detail correctly?

> Each line on the invoice detail has its FK pointing to the Article's ID, but sometimes the user needs to modify or add some text to the article description just for that
> invoice. Or sometimes he/she needs to insert a "free" line (pointing to no article at all) just filling the description.

> So my "big" doubt is: Is this a case for "denormalization" ? Should I add a "description" field to the invoice detail (and 90% of the time having exactly the same description of the article's table!!)

> Or should I have the "description" field in a separate table. In this case I don't imagine how to update that table, as the user enters the data in a DBGrid (I work with Delphi / IBDac)

> I hope I'm clear with my question!

> Thanks!


Mit freundlichen GrĂ¼ssen
Hannes Streicher mailto:HStreicher@...