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SSCommitted
      
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SSCommitted
      
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This is an excellent question, thank you. I answered it correctly because for years I cannot find the answer to the following question: why would anyone ever consider casually using float data type? I understand that there might be some specific scenarios where the inaccuracy of calculations are not important and the range of the numbers is huge, but using float for no good reason is astonishingly bad not to say plain silly. The query in Qotd is one fine example demonstrating this point.
Oleg
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SSCrazy
      
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| Thanks for the question, I had to puzzle it out for a while, but got it right.
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SSCommitted
      
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for testing folating point the same can be written as
DECLARE @i float,@rc int set @i = 0 while @i <> 1 begin set @i = @i + 0.1 end select @i
then the loop never executes.
I observer some intrested behavior of floating point
DECLARE @i float,@rc int set @i = 0 while @i <> 1 begin set @i = 0.8999 + 0.1 end select @i
the above will never executes. we use 0.1 instead of 0.8999 other wise we can use 0.2,0.3,0.4,0.5,0.6,0.7,0.8.but when i added 0.9 it executes
and show 1 as answer.
Malleswarareddy I.T.Analyst MCITP(70-451)
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SSCarpal Tunnel
       
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The answer was almost obvious from the "do not run it on production server" recommendation.
But, a good question for highlighting the pitfalls of "float".
Cheers, - Mark
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Hall of Fame
       
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The only possible use for the float datatype that I have found is in the calculations used in astro-physics, where the distance between stars and galaxies is an approximation, at best
____________________________________________ Space, the final frontier? not any more... All limits henceforth are self-imposed. “libera tute vulgaris ex”
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SSCoach
         
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SSCrazy Eights
        
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Ten Centuries
      
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| Very interesting question and great explanations. Thanks
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SSC-Enthusiastic
      
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| isn't it possible to use approximation if one is not specific of the exact value of the approximation, like "less than" and "greater than" ?
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