Hi,

I have a table with 4 Float Fields eg: a,b,c,d

d is entered by the user but is the result of a+b+c

I wanted to create an SQL to filter out all records where d<>a+b+c

I used SELECT * FROM MyTable WHERE (a+b+c)<>d

But the result included records where a+b+c=d as well?

Tested the same on Access and no problem. Maybe it is something I am doing wrong?
Thanks

Dave,

> I have a table with 4 Float Fields eg: a,b,c,d
>
> d is entered by the user but is the result of a+b+c
>
> I wanted to create an SQL to filter out all records where d<>a+b+c
>
> I used SELECT * FROM MyTable WHERE (a+b+c)<>d


Never use direct equality tests on floats like that.

> But the result included records where a+b+c=d as well?


Try "WHERE ABS((a+b+c)-d) > 0.01" ...or whatever level of precision
makes sense in the context of your app.

Eryk

PS: You might want to read up on BCD fields - they may be more
appropriate than floats if you are doing stuff like this.

Dave


Float fields are notorious for this. Its a case of what you see is not necessarily what you get You'll need to round each field in some way. Then again Tim may need to make sure the results for a float field are only returned to the precision specified. I'm not sure which it should be in ElevateDB, in DBISAM it was definitely your responsibility.

Roy Lambert

Roy,

<< Float fields are notorious for this. Its a case of what you see is not
necessarily what you get You'll need to round each field in some way.
Then again Tim may need to make sure the results for a float field are only
returned to the precision specified. I'm not sure which it should be in
ElevateDB, in DBISAM it was definitely your responsibility. >>

ElevateDB is the same as DBISAM in this regard.

--
Tim Young
Elevate Software
www.elevatesoft.com

Eryk,

<< PS: You might want to read up on BCD fields - they may be more
appropriate than floats if you are doing stuff like this. >>

DECIMAL is the proper term with ElevateDB.

http://www.elevatesoft.com/edb1sql_exact_numeric_types.htm

--
Tim Young
Elevate Software
www.elevatesoft.com