Mr. & Mrs.Smith!

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Mr. & Mrs.Smith!

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VM-723206

Posted Tuesday, April 28, 2009 11:35 PM

SSChasing Mays

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Comments posted to this topic are about the item Mr. & Mrs.Smith!

Post #706481

SanjayAttray

Posted Wednesday, April 29, 2009 8:37 AM

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Aha... This one's easy.

SQL DBA.

Post #706887

MattieNH

Posted Friday, May 01, 2009 1:02 PM

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This question reminded me of something that I've never understood. You would get the same answer to the question if the where statement looked like this:

where lastname like 'Smith%'
and firstname like '%a%'
and ID in ()

that is, without the parentheses. What I don't understand is why people write code with parentheses when all the conditions are equivalent in evaluation. If all you have are ANDs or all you have are ORs, what purpose is there to putting parentheses around the individual conditions? I was taught that you only needed parentheses when you were combining ANDs and ORs. Is that true, or do all these what seem to be extra parentheses have some value?

Thanks,
Mattie

Post #708704

Carlo Romagnano

Posted Saturday, May 02, 2009 7:45 AM

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I agreed with you. I do not like unneeded parenthesis.

Post #708916

L' Eomot Inversé

Posted Tuesday, June 16, 2009 2:54 PM

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Carlo Romagnano (5/2/2009)

I agreed with you. I do not like unneeded parenthesis.

I agree too, about not liking unnecessary parentheses. But I can hazard a guess as to why people do it: perhaps they first learned a language where parentheses around conditionals were mandatory (if X then Y not allowed, it has to be of (X) then Y) and/or they used languages where words like "and" and "or" were heavily overloaded ( X = a or b might mean either X = (a or b) or (X = a) or b depending on the types of X, a and b, and could actually be ambiguous for some type combinations) amnd got into the habit os using brackets all the time.

Different point: this question points up one of the stupidities of SQL: () represents a set of columns/values, except in the single case where is the empty list, in which case using it to represent a set will give you a syntax error. That's the sort of inconsistency that really irritates me (as a former language designer) - it makes the syntax slightly harder to analyse so that writing a compiler/tokenizer/interpreter is harder; and it makes the language slightly more difficult to learn; and (this is the crunch point) it sometimes makes the language quite a lot harder to generate dynamically.

Tom
Que conclure à la fin de tous mes longs propos? C'est que les préjugés sont la raison des sots. (Voltaire, 1756)

Post #736053

kapil_kk

Posted Monday, February 18, 2013 11:52 PM

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EASY ONE!!

Post #1421447

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