At 21:42 23/02/2004 -0300, you wrote:

> Hello,
>
> This is my first message on this list. Hello to everybody! :-)
> I'm new with Delphi/Firebird (long time from DOS) and there is some
>things that I does not understand.
> I'm developing a Win version of my software and learning the concept
>of Client/Server.
> The use of a foreing key is only necessary when we need cascade
>updates/deletes? Instead of this cases, we can use the JOIN statement.
>There is improvement using FK?
> Why I can't create a foreing key after the tables has some data ou
>triggers? There is a special rule for this?
>
> Thank you all for the attention.
>
> Platform: WinXP Pro, Delphi 6 Pro (SP2) and FireBird 1.5.
>
>--
>
>..::
> Marcello Fontolan
> marcello@...
>::..
>

Oi Marcello,

FK's are to impose referential integrity...

You could join on any column, not necessarily FK's, but will generally make
join on PK/FK since if you have a relationship between two tables this will
lead to PK/FK relationship...

If you prefer send me a private e-mail and we could talk in portuguese...

ate mais...




Alexandre Benson Smith
Development
THOR Software e Comercial Ltda.
Santo Andre - Sao Paulo - Brazil
www.thorsoftware.com.br

----------


---
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.592 / Virus Database: 375 - Release Date: 18/02/2004


[Non-text portions of this message have been removed]