RE: Designer Question - Arc

  • From: Surendra.Tirumala@xxxxxx
  • To: sfaroult@xxxxxxxxxxxx, oracle-l@xxxxxxxxxxxxx, Surendra.Tirumala@xxxxxx
  • Date: Tue, 11 Jan 2005 09:04:58 -0500

Hi Stephane,
 
Thanks for your suggestion.
My child table "A" should be a single table as it contains some codes(say
"Budget Units" or "Expenditure Codes") which should be allocated to 
different mutually exclusive things which are spread accross tables "B", "C"
and "D".
And the PK on "A" (on BUs or ECs) is the driving point for couple of other
things.
 
Surendra Tirumala
-----Original Message-----
From: Stephane Faroult [mailto:sfaroult@xxxxxxxxxxxx]
Sent: Tuesday, January 11, 2005 8:51 AM
To: oracle-l@xxxxxxxxxxxxx; Surendra (WFD-FK)'
Subject: Re: Designer Question - Arc


Don't you rather think that you have three tables A1, A2 and A3 with FKs to,
respectively, B, C and D which are all three subtypes of A, which means that
their PKs are non-overlapping sets and are also FKs referencing A ?

Regards, 

Stephane Faroult 

RoughSea Ltd 
http://www.roughsea.com 


On Tue, 11 Jan 2005 08:10 , 'Tirumala, Surendra (WFD-FK)'
<Surendra.Tirumala@xxxxxx> sent:



Hello All,

I have a child table "A" which has three mutually exclusive FKs to three
different PKs(on tables "B","C" and "D").
Concluding that this is a straight forward case to use Arc concept in
Designer, I have compelted the design.
Now I am working on enforcing the mutually exclusiveness. 
As "Generate TAPI" gives some skeleton code for this purpose,
can anyone please let me know if you have evaluated this code and used it?

I am not quite sure how far I should go.
To begin with, I am thinking of using some simple check constraints to check
only one of the three columns is NOT NULL
and others are NULL.

Please share some thoughts.

Thanks,
Surendra Tirumala


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