Re: Constraint problem: number of rows...

From: Volker Hetzer <volker.hetzer_at_ieee.org>
Date: Mon, 13 Jun 2005 22:32:58 +0200
Message-ID: <d8kqhq$h20$1@nntp.fujitsu-siemens.com>

DA Morgan wrote:

> Volker Hetzer wrote:
> 

>> Hi!
>> I've got a rather stupid constraint problem:
>> There's a table with data on PCB symbols (like "7400" or "Resistor").
>> Per symbol there's the number of pins on the symbol.
>> Now, another table is supposed to have as many rows (per symbol)
>> as there are pins.
>> Is there any way I can have a constraint checking this?
>>
>> Lots of Greetings and thanks!
>> Volker

> 
> 
> Tom Kyte has dealt with this at least a few times and explained how
> best to accomplish this. I'd suggest checking http://asktom.oracle.com.

There is indeed something in there that could work: http://asktom.oracle.com/pls/ask/f?p=4950:8:11403979146324286545::NO::F4950_P8_DISPLAYID,F4950_P8_CRITERIA:42170695313022 Ok, that question deals with a special case of 0 and 1 but I think that could be extended:
The symbol table has one attribute with the pin count that should be there and one attribute with the current pin count. Then a trigger on the pin table updates the current count and a deferred constraint on the symbol table checks that they are identical at the end of ach transaction.

> Get back if you don't find it.
Sorry, got back anyway... :-)

Lots of Thanks!
Volker Received on Mon Jun 13 2005 - 15:32:58 CDT