Alastair, Checking for "[unknown]" is programmatically the same as looking for the field to be null. If the user misspells the word unknown, the address line will seem valid. The thing I like about null is that it is boolean and exact. Either value exists or no value exists. We don't assume user error because no value exists.
I guess then with the wide array of feelings on the entire NULL theology, it is really a great thing that with R:Base the developer has the ability to control the logic of it provided she/he understands all the considerations. "Long live the NULL" Thom At 09:43 PM 07/24/2002 +0100, you wrote: >Yes, Albert & Thom, I agree - and disagree: > >How do you know, for instance, which of these addresses is correct: > >Mr. Fred Bloggs, >Bloggs House, >Bloggs Street, >Bloggstown, >Bloggscounty, >Bloggscountry, >Bloggszip > >or > >Mr. Fred Bloggs, >Bloggs Street, > >Bloggstown, >Bloggscounty, >Bloggscountry, >Bloggszip > >whereas > >Mr. Fred Bloggs, >[Unknown] >Bloggs Street, >Bloggstown, >Bloggscounty, >Bloggscountry, >Bloggszip > >tells you that somebody didn't know the house name or number or whatever. > >Of course, you have to do some extra work with the third option but it's >relatively simple to set up an "if LineNo_n = [Unknown] then set LineNo_n = >' ' " when you use the address. > >But I did say that "most of the time", "usually", and "that I didn't always >follow my own advice" and you've hit one of the ones where I'm too lazy to >do it. I have say in my defence that English addresses tend to use more >lines than in many other countries for some reason and, also, that the >problems encountered with EQNULL should not be too frequent with addresses. > >The point was to avoid the EQNULL problem AND clarify data wherever >possible - not to slavishly follow a principle. Sometimes a compromise needs >to be accepted but filled with blanks - any number of blanks - is a no-no in >any situation. > >Regards, >Alastair. > > > > >----- Original Message ----- >From: "Thomas J Cimicato" <[EMAIL PROTECTED]> >To: <[EMAIL PROTECTED]> >Sent: Wednesday, July 24, 2002 8:44 PM >Subject: Re: EQNULL > > > > I second that motion. A null address line should not be blank filled or >set > > to some value for value's sake. If the address is null, I can check for a > > null value. > > > > Thom > > > > > > At 02:26 PM 07/24/2002 -0400, you wrote: > > >Alastair, I will agree, but only for FOREIGN KEYed columns. Addresses, > > >for example, occasionally need two lines, and Address2 is most often > > >NULL. Likewise for telephone extensions, etc. > > > > > >"Alastair Burr" <[EMAIL PROTECTED]> wrote: > > > > > > >At the risk of either repeating myself or making myself unpopular I >would > > > >also say that _most of the time_ a column that allows nulls is poor >design. > > > > > > > >Yes, I know it can't always be helped but _usually_ some unlikely >number can > > > >be used for "unknown" and text can easily be set for "unknown". Thus >forcing > > > >the user to make a choice even if it's "I don't know". I'm sure that >this is > > > >better than "I can't be bothered to decide" - at least you know it's a > > > >positive unknown rather than an unfilled field. > > > > > > > >I can't say that I do not have any column in any database that can be >null > > > >but I always try to make it part of the design. When I do find that I > > > >_think_ I need a null column it usually means that the table needs to >be > > > >split into two tables. > > > > > > > >Just my two-pennyworth, > > > >Regards, > > > >Alastair. > >================================================ >TO SEE MESSAGE POSTING GUIDELINES: >Send a plain text email to [EMAIL PROTECTED] >In the message body, put just two words: INTRO rbase-l >================================================ >TO UNSUBSCRIBE: send a plain text email to [EMAIL PROTECTED] >In the message body, put just two words: UNSUBSCRIBE rbase-l >================================================ >TO SEARCH ARCHIVES: >http://www.mail-archive.com/rbase-l%40sonetmail.com/ Thomas J Cimicato President Integrated Check Technologies Collect-A-Check, Inc. ------------------------------------------------------------ Bus:800.338.0676 x3120 614-55-CHECK Fax:614-552-4439 Mailto:[EMAIL PROTECTED] www.ICheckTech.com ================================================ TO SEE MESSAGE POSTING GUIDELINES: Send a plain text email to [EMAIL PROTECTED] In the message body, put just two words: INTRO rbase-l ================================================ TO UNSUBSCRIBE: send a plain text email to [EMAIL PROTECTED] In the message body, put just two words: UNSUBSCRIBE rbase-l ================================================ TO SEARCH ARCHIVES: http://www.mail-archive.com/rbase-l%40sonetmail.com/
