Dan Waters
dwaters at usinternet.com
Mon Mar 16 11:35:16 CDT 2009
If I was designing that system, I would have two fields. One is the SSN, the other is a unique hospital defined number for people without a SSN. Either could be Null, but one of them must be filled in correctly. And neither could be a FK. Dan -----Original Message----- From: dba-sqlserver-bounces at databaseadvisors.com [mailto:dba-sqlserver-bounces at databaseadvisors.com] On Behalf Of Susan Harkins Sent: Monday, March 16, 2009 11:27 AM To: Discussion concerning MS SQL Server Subject: Re: [dba-SQLServer] NULLs Well, exactly... that's my point -- you don't have to have a ss# to get care. If the validation rules require a 9 digit number, how do you under, "None?" The question becomes, which is more important -- the no null rule or data validation? Which trumps? Susan H. > Last time I looked at the emergency room, I never saw anyone get turned > away > for lack of social security. again, I'm just playing devil's advocate, > simply to keep things interesting. _______________________________________________ dba-SQLServer mailing list dba-SQLServer at databaseadvisors.com http://databaseadvisors.com/mailman/listinfo/dba-sqlserver http://www.databaseadvisors.com