On Thu, 22 Feb 2007, Erick Papadakis wrote:
Why should a NULL be different from an empty string, what's the big mysterious difference?
Long ago and far away, when I was in the Army, we had quite a few soldiers whose name took the form 'John NMI Doe.' That's because the Army -- even before computers were ubiquitous -- needed something in the forms for middle initials. If you did not have a middle name or initial, one was assigned to you: NMI (No Middle Initial). This did not mean that the middle initial was unknown (NULL), but that it did not exist (blank). If you have a credit card, would you prefer the balance to be blank or unknown? How would the bank select all those with no balance rather than those for whom a balance is unknown? I'm sure you can think of dozens of more situations like these. Rich -- Richard B. Shepard, Ph.D. | The Environmental Permitting Applied Ecosystem Services, Inc. | Accelerator(TM) <http://www.appl-ecosys.com> Voice: 503-667-4517 Fax: 503-667-8863
