Re: Simple question on data design...

>> You forget: newsgroups are for helping others- often with less
knowledge or experience... <<

No, I don't. That is why my posting was so detailed. If anything, I am pendantic.

>> Your piss-piddley Data Definition Language is useless when the data
is already defined... <<

It is not my DDL; it came with the SQL Standards (I just helped write them). The DDL is what defined the data, so it is vital to knowing how the data is structured.

Most beginning SQL Programmers cannot design a schema correctly. The bad schema leds to horrible queries and performance. If they came from ACCESS or other non-SQL languages, where the tables are defined either automatically or by graphic interfaces, they never learn DDL.

>> by the_way, your_underscore_characters SUCK if you ask me. <<

Look at the human factors research done at the University of Maryland in the late 1970' and early 1980's on code readability. Do you have later research to contradict these studies? I think it was about 30 or 35 of them, done mostly by students, but I woudl have to look it up.

>> Obviously you can't read 'personal pseudo code', however
elementary. <<

You forgot to include a manual for it <g>. Use of DDL is a basic part of Netiquette in these newsgroups. We once had someone on the SQL Server Newsgroup post his personal pseudo code, and we came up with eight different schemas. If you have a copy of my book, DATA & DATABASES section 22.9, I came up with five 3NF schemas from the same rules.

>> Record 4 times??!! What the fuck are you talking about? <<

I have one and only one address. I get my billing, shipping, etc. at it. In your design, you will have to repeat my information four times, changing the address type flag for each of the four possible codes.

>> Do you record your client 2 times because he may be male or female?
<<

Actually, the ISO Standard sex codes are

 0 = unknown
 1 = male
 2 = female
 9 = lawful persons (corporations, governmental organizations, etc.)

That is another problem beginners have -- they don't know standards or where to research them, so they invent their own. In your example, did you look up the SAN (Standard Address Number) used in the book trade?

>> 'Nothing inherit'??? You're either talking about the OOP paradigm,
or genetics, neither of which has jack to do with my pseudo code or your DDL bullshit... <<

Then please explain why a billing address is LOGICALLY different from a shipping address. Are the streets a different size? Can only certain vehicles travel to them? etc. Nope; an address is an address. Now a foreign address, with a totally different set of rules and regulations would be a candidate for a different table.

After 10 years on the SQL Standards Committee, and 20+ of database experience, I have seen the same mistakes over and over. Rather than let someone continue to do the same old mistakes, I try to educate them so they can go onto new and exciting mistakes!! Received on Fri Nov 09 2001 - 15:53:54 CET