Oracle-L: RE: Design question.

From: Mercadante, Thomas F <NDATFM_at_labor.state.ny.us>
Date: Fri, 31 May 2002 08:33:47 -0800
Message-ID: <F001.00471056.20020531083347@fatcity.com>

I agree that "Not Good" might characterize this - what it points out is "not good" table design. the parent table now will have a row with two unique items - the existing primary kay, and a combination of two other columns.

I would review the tabl3e design and decide if something else needs to be done.

Tom Mercadante
Oracle Certified Professional

-----Original Message-----
Sent: Friday, May 31, 2002 12:07 PM
To: Multiple recipients of list ORACLE-L

Chris,

Is there a unique constraint based on the two fields in the parent table? If so it might work OK. Still there are the problems of referential integrity, orphan records, etc. If there isn't a unique constraint in the parent table, you can also add in potential many-to-many relationships as a problem to.

Basically I'd say this falls into the "Not Good" category.

Jerry Whittle
ACIFICS DBA
NCI Information Systems Inc.
jerome.whittle_at_scott.af.mil
618-622-4145

-----Original Message-----
Sent: Friday, May 31, 2002 10:33 AM
To: Multiple recipients of list ORACLE-L

We have a designer that is adding a FK on two columns from one table to
another. These two columns are not in the parent table's primary key.

So we are kind of scratching our heads wondering if you can, from a proper
design point of view, create such a FK? It appears that if you update one of the two columns in the child table then you would need to create a new record in the parent table.

Thoughts??

--

Please see the official ORACLE-L FAQ: http://www.orafaq.com
--

Author: Mercadante, Thomas F
INET: NDATFM_at_labor.state.ny.us

Fat City Network Services    -- (858) 538-5051  FAX: (858) 538-5051
San Diego, California        -- Public Internet access / Mailing Lists
--------------------------------------------------------------------

To REMOVE yourself from this mailing list, send an E-Mail message to: ListGuru_at_fatcity.com (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing). Received on Fri May 31 2002 - 11:33:47 CDT