precision in access versus excel

[martygeo]

I wanted to validate an SQL query that involved a modest algebraic solution
against the same solution in excel and noticed that my answers were off by
about 0.5%. As far as I can tell my algebra is fine in both cases. Can anyone
tell me if I should expect rounding error or differences in precision between
a solution in excel and one using a SQL query? I'm not a programmer, so don't
have a full grasp of how solutions are arrived at in such a query. My
equations use exponents and square roots to solve a simple geometric
projection problem.

Thanks
Martin

 

[Jeff Boyce]

Martin

You don't mention how many decimal places you need for accuracy.

In many instances, having 4 decimal places is enough ... and you can use the
Currency datatype in Access to achieve this.

If you use the Single or Double datatypes, they store as binary, leading to
.... ?!rounding errors!

More info, please...

Regards

Jeff Boyce
Microsoft Access MVP


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