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Re: Query precision issue

From: Michael Satterwhite (michaelweblore.com)
Date: Tue Oct 26 2010 - 09:49:02 CDT


This is a problem that is as old as computers. Floating point decimal data
does not translate directly into binary. Whole numbers are (usually) fine, but
fractions bring out this problem. I remember writing comparisons where I
wanted a value of "10.203" correct to 3 decimal places as

        if abs(x -10.203) < 0.00001

On Monday, October 25, 2010 12:15:49 pm Sairam Krishnamurthy wrote:
> All,
>
> I have simple query like 'select * from table1 where
> column1=-107.6898780000'. This returns an empty set. But there is data
> corresponding to this value of column.
>
> When I looked more into it, it seems like a precision issue. The value
> for column1 is -107.689878.
>
> More interesting is that the following query fetches the row,
>
> 'select * from table1 where column1=-107.689878000'
>
> Note that there are only three trailing zeros in the second query while
> there were four in the first.
>
> Can somebody help me to find out the problem? I can very well truncate
> the trailing zeros when querying, but I am interested in finding why an
> additional trailing zero returns an empty set.

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