John R Bartow
jbartow at winhaven.net
Sat Jan 3 21:27:30 CST 2015
I agree with Jim. 1-1 relationships can be set up if desired in order to try and be more strictly normalized but it rarely makes sense these days and it does complicate any UI or queries structures. I think I've only ever used one 1-1 table relationship in my own developments. I'll have to look and see if I can find out why I did that. I saw a lot of 1-1 relationships in a very large, government agency, database schema in the past but after numerous years of working with it there was never an entry in any of those tables. -----Original Message----- From: accessd-bounces at databaseadvisors.com [mailto:accessd-bounces at databaseadvisors.com] On Behalf Of Jim Dettman Sent: Sunday, November 30, 2014 1:57 PM To: 'Access Developers discussion and problem solving' Subject: Re: [AccessD] Confused by One to Many versus One to One Bill, It's pretty rare to have a 1 to 1. Pretty much everything will be a 1 to M or a M to M. Jim. -----Original Message----- From: accessd-bounces at databaseadvisors.com [mailto:accessd-bounces at databaseadvisors.com] On Behalf Of Bill Benson Sent: Friday, November 28, 2014 07:52 PM To: 'Access Developers discussion and problem solving' Subject: [AccessD] Confused by One to Many versus One to One I almost never make relationships one to one, and yet my databases always seem to "work." By work, I mean that I never seem to run into situations where I cannot accomplish what I want to, in terms of record insertion, queries, etc. So I now have a situation where maybe that is not a good idea. I have Order and Product tables, one order can contain many products. So I required an OrderProducts table to distribute the same OrderID across numerous ProductIDs. My question is, should the relationship between the Order and OrderProduct, on the OrderID and FKOrderID, be 1-to-1, or 1-to-many? Likewise, the same question for the OrderProduct and the Product, on the ProductID and the FKProductID? -- AccessD mailing list AccessD at databaseadvisors.com http://databaseadvisors.com/mailman/listinfo/accessd Website: http://www.databaseadvisors.com -- AccessD mailing list AccessD at databaseadvisors.com http://databaseadvisors.com/mailman/listinfo/accessd Website: http://www.databaseadvisors.com