Great article on NULLs and queries

website@infoadvisors.com — Thu, 01 Mar 2007 19:11:00 GMT

Michael Coles has a couple of good articles on NULLs, ANSI, SQL Server, the Four rules of NULLs, and unknowns:

http://www.sqlservercentral.com/columnists/mcoles/fourrulesfornulls.asp

http://www.sqlservercentral.com/columnists/mcoles/2829.asp

In one of the first articles I wrote for SQL Server Central, I talked about SQL NULLs and three-valued logic (Four Rules For NULL). In this article I take it all back...

No, not really, but stay tuned as we talk about the darker side of ANSI NULLs.

The Original Four Rules

The original four rules I proposed for NULL-handling are all reproduced here in Figure 1.

Figure 1. The original "Four Rules"

Karen Lopez: Musings on Data, Process, and Architecture

Great article on NULLs and queries

The Original Four Rules