Thanks
I have always used integer's, never floats or doubles, I realised back in
the 90's that was a mistake when implementing credit card transactions.
Rounding errors bite hard.
I have always decided at the start of a project what was the maximum
precision needed, usually 2 decimal places but occasionally more. I can see
with kmymoney 4 digits is the best because I believe that is normal for
shares. however I don't do shares so I could be wrong.
Just looked it up, shares below $1.00 is to 4 decimal places, 2 places
otherwise.
I can see storing it using numerator denominator is more flexible.
Chris
On 15/11/2022 5:42 pm, Thomas Baumgart via KMyMoney-devel wrote:
On Dienstag, 15. November 2022 01:01:03 CET Chris via KMyMoney-devel wrote:
I was going through the database tables when a file was stored as sqlcipher.
I came across something I haven't seen before and I was wondering why it was
that way
Transaction values are stored as text strings but with unusual divisors.
For example the value 18.95 may be stored as "1895/100" which is 1895
divided by 100 = 18.95. All and good
but there are other ones which confuse me as to why its done this way.
Examples are ...
unformatted => formatted
258/25 => 10.32
124/25 => 4.96
-273/50 => -5.46
1/2 => 0.5
Can some one explain why it is done that way?
See
https://stackoverflow.com/questions/3730019/why-not-use-double-or-float-to-represent-currency
for the details of why we use the "numerator/denominator" representation.
The ones that confuse you are simply canceled to the smallest denominator.
That's a
feature/requirement of the underlying library.
124/25 => 4.96
124/25 * 4/4 => 496/100
