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 "Real" copy of Codd's 12 (13) Rules for RDBMS Rate Topic Display Mode Topic Options
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 Posted Thursday, August 12, 2010 8:53 AM
 SSC-Forever Group: General Forum Members Last Login: Yesterday @ 10:35 PM Points: 42,070, Visits: 39,452
Post #968249
 Posted Thursday, August 12, 2010 9:03 AM
 SSCrazy Eights Group: General Forum Members Last Login: 2 days ago @ 4:00 PM Points: 9,824, Visits: 11,895
Post #968258
 Posted Thursday, August 12, 2010 9:17 AM
 SSChasing Mays Group: General Forum Members Last Login: Friday, January 22, 2016 2:15 PM Points: 600, Visits: 3,852
Post #968284
 Posted Thursday, August 12, 2010 9:58 AM
 SSChasing Mays Group: General Forum Members Last Login: Friday, January 22, 2016 2:15 PM Points: 600, Visits: 3,852
 Not that I'm trying to put an end to this logic discussion, I'm not: but look. Can't we accept that in certain cases NULLs are useful and in others, they're not? The truth of a statement requires it to be both valid and sound. But since mathematics and logic are abstracted beyond individual cases, they can not be said to be sound at all (there is a NULL for their soundness). In which case, Mathematics and logic can be said to be neither true nor false, only valid or invalid.I bring this up since I believe that we're trying to paint with too broad of strokes (yes, i.e., it depends) and if we're looking for The Truth of NULLs in logic, we're attempting the impossible. Conversly, I'm not saying that it is not worthy of consideration - of course it is. Before, a good example of blood pressure was used as an example where the unknown was needed. That's all well and good. On the other hand, look: think of a GL table - there is no need to go adding NULLs everywhere when we add a new GL number - empty means there are no charges to that account yet. It isn't complicated - we decide that those are the rules we're following for this table and it's that simple. If someone fails to enter charges to the account - it is still going to show zero. But how is our DBMS to know when someone is failing to enter the charges anyway? Most of the time in this scenario, we're fine with assuming that if no records show charges with account X, then there are no charges (credits or debits) associated with it. It works - we're forced to be pragmatic since we're not omniscient. ______________________________________________________________________The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge. - Stephen Hawking
Post #968348
 Posted Friday, August 13, 2010 10:36 PM
 SSC-Forever Group: General Forum Members Last Login: Yesterday @ 10:35 PM Points: 42,070, Visits: 39,452
 mtillman-921105 (8/12/2010)I have to disagree with you there Jeff. The utility of SQL Server, and all RDBMS in general, is for business. Why remove it from its context? Business is its reason for being. This reminds me of Wittgenstein getting frustrated with philosophers and exclaiming, "Don't think! Look!" This is an interesting discussion, but I'm going to keep trying to pull it back down to Earth as I think Wittgenstein would. NULLs are here for our use rather than vice-versa. NULLs are only what we define them to be; nothing more and nothing less.Heh... you just can't help knocking rings, can you? I didn't say that SQL Server wasn't used for business nor did I try to remove it from that context. I said business has nothing to do with the definition of NULL. You're also very incorrect if you think SQL Server is used only for business as you know it.Also, you haven't been listening. I support and embrace the use of NULLs. I don't need a lecture on NULLs being "here for our use rather than vice-versa". If you believe in that, then we're probably on the same side on that issue. --Jeff Moden"RBAR is pronounced "ree-bar" and is a "Modenism" for "Row-By-Agonizing-Row".First step towards the paradigm shift of writing Set Based code: Stop thinking about what you want to do to a row... think, instead, of what you want to do to a column." Helpful Links:How to post code problemsHow to post performance problems
Post #969344
 Posted Friday, August 13, 2010 10:38 PM
 SSC-Forever Group: General Forum Members Last Login: Yesterday @ 10:35 PM Points: 42,070, Visits: 39,452
 mtillman-921105 (8/12/2010)Not that I'm trying to put an end to this logic discussion, I'm not: but look. Can't we accept that in certain cases NULLs are useful and in others, they're not? You should have stopped there. That's all I've been trying to say during this whole thing. --Jeff Moden"RBAR is pronounced "ree-bar" and is a "Modenism" for "Row-By-Agonizing-Row".First step towards the paradigm shift of writing Set Based code: Stop thinking about what you want to do to a row... think, instead, of what you want to do to a column." Helpful Links:How to post code problemsHow to post performance problems
Post #969345
 Posted Saturday, August 14, 2010 10:10 AM
 SSCrazy Eights Group: General Forum Members Last Login: 2 days ago @ 4:00 PM Points: 9,824, Visits: 11,895
 Jeff Moden (8/13/2010)mtillman-921105 (8/12/2010)Not that I'm trying to put an end to this logic discussion, I'm not: but look. Can't we accept that in certain cases NULLs are useful and in others, they're not? You should have stopped there. That's all I've been trying to say during this whole thing. The real problem of course is that although most of us (I was tempted to say all those of us who are rational, but I didn't want to give offence so I refrained) hold that opinion, there are some people who regard NULLs as an device of the devil and will not accept that any useful language (or algebra or calculus) of relations could possibly include such an evil concept (or even worse, use a logic which is not good old classical 2-valued logic - no shades of grey in the semantics of their truth values). Tom
Post #969404
 Posted Saturday, August 14, 2010 1:23 PM
 SSC-Forever Group: General Forum Members Last Login: Yesterday @ 10:35 PM Points: 42,070, Visits: 39,452
 Heh... Well said, Tom. I LOVE "evil concepts" especially in T-SQL. --Jeff Moden"RBAR is pronounced "ree-bar" and is a "Modenism" for "Row-By-Agonizing-Row".First step towards the paradigm shift of writing Set Based code: Stop thinking about what you want to do to a row... think, instead, of what you want to do to a column." Helpful Links:How to post code problemsHow to post performance problems
Post #969426
 Posted Monday, August 16, 2010 8:36 AM
 SSChasing Mays Group: General Forum Members Last Login: Friday, January 22, 2016 2:15 PM Points: 600, Visits: 3,852