Subject Re: [firebird-support] Precision in stored procedures
Author Tomasz Tyrakowski
Just one remark in addition to what Thomas Steinmaurer has already shown
you. Do not believe blindly in what stored procedure debuggers show you.
What you see in the debugger window, as being the value of a SP
variable, is not neccesarily the same as the actual value in the server
process. Try to check (inside the procedure itself) whether the result
fits in a range defined by the desired precision, e.g.:

if (A < 8.6999 or A > 8.7001) then
[raise an exception or signal the error in other way]

and run the modified procedure without the debugger. Inserting the
result into a table may be a good idea as well, provided that you check
the inserted value by other means than by looking at it ("seeing"
requires conversion to string, which may or may not be accurate).


On 2012-03-07 21:16, Rick Debay wrote:
> No one? My (probably unjustified) fear is that since the variables are
> stored in a four byte primitive instead of a packed-decimal like format,
> I may randomly run in to this.
> -----Original Message-----
> From:
> [] On Behalf Of Rick Debay
> Sent: Tuesday, March 06, 2012 12:08 PM
> To:
> Subject: [firebird-support] Precision in stored procedures
> If a stored procedure has three variables
> And a function is evaluated with these values
> A = B / C;
> A = 7.3 / 0.839080459770115
> Then the value stored in A will be 8.7 not 8.70000000000119 (a firebird
> stored procedure debugger) or 8.6999999999999994041095890410959 (windows
> 7 calculator), correct?
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