Oracle FAQ Your Portal to the Oracle Knowledge Grid
HOME | ASK QUESTION | ADD INFO | SEARCH | E-MAIL US
 

Home -> Community -> Usenet -> comp.databases.theory -> Re: How to ensure data consistency?

Re: How to ensure data consistency?

From: --CELKO-- <jcelko212_at_earthlink.net>
Date: 9 Sep 2004 08:57:46 -0700
Message-ID: <18c7b3c2.0409090757.4133eee7@posting.google.com> 





>> there still is the problem that the main table may contain entries

for which there are no [rows in] subtables. <<



In intermediate SQL-92, all table level constraints are TRUE for an
empty table, so you need to have full SQL-92 and use a cross table
constraint.  That would be either a CREATE ASSERTION statement or a
CHECK() that has a predicate that references the other table.
Received on Thu Sep 09 2004 - 10:57:46 CDT












Original text of this message













  HOME |
  ASK QUESTION |
  ADD INFO |
  SEARCH |
  E-MAIL US