INCORECT SUM

[delphIBase]

MY PROBLEM:

I made a stored procedure which extract the following values from a table

UNITPRICE ITEMQTY
====================== ===========

12.52 16
59.25 6
480.70 1
841.56 10
8786.63 2

and compute amount with the following formula

amount=(unitprice/1.1)* quantity

having defined amount a numeric(15,2) the stored procedure I created returned the following values

AMOUNT
======================

182.05
323.19
437.00
7650.56
15975.69

Using the statement "select sum(amount) from myproc" to get the sum I got

SUM
======================

24568.48

question:
Given the amount extracted why did I arrived with 24568.48 as sum instead of 24568.49 and how will i arrive with the accurate results?THANKS!:>

 

[unclejimbob]

Using your figures the amount I get is 24568.504

Here is what I used:

create table test1
(
unitprice numeric(15,2),
itemqty integer
);
commit;

insert into test1 values (12.52,16);
insert into test1 values (59.25,6);
insert into test1 values (480.70,1);
insert into test1 values (841.56,10);
insert into test1 values (8786.63,2);
commit;


select sum((unitprice/1.1)*itemqty) from test1;

Unless you need 15 digits of precision I'd be inclined to
reduce it to numeric(9,2), at least this will avoid the problem where IB turns it into a real when using a
precision > 9

I may be wrong about this its been a few years since I last read the user manual

I tried it with different precisions 9,2 and 7,2 and got the same result so maybe there is something in the sp that
I am missing.