Way for moving stored procedure from Firebird to SQL Server - sql-server-2008

Question

I have working SP on Firebird and can'not find the way to translate code to MS SQL server SP
here is the code:
I have one table to get data from.
One fields called "iznos" for data summary and one field for recognite diference for summary by category
create or alter procedure SOME_PROCEDURE (
B_Date date,
E_Date date)
returns(
Dat date,
Value1 decimal(18,2),
Value2 decimal(18,2),
Value3 (18,2))
AS
BEGIN
FOR
SELECT gk.date
FROM gk
WHERE
gk.date BETWEEN :B_Date AND :E_Date
GROUP BY 1
INTO :Dat
DO
BEGIN
/* Value 1 */
SELECT sum(iznos) from gk where gk.category=1 and gk.datum=:Dat
INTO :Value1;
/* Value 2 */
SELECT sum(iznos) from gk where gk.category=2 and gk.datum=:Dat
INTO :Value2;
/* Value 3 */
SELECT sum(iznos) from gk where gk.category=3 and gk.datum=:Dat
INTO :Value3;
suspend;
end
end

Answer 1

You can solve this using PIVOT:
select datum, [1] as Value1, [2] as Value2, [3] as Value3
from (
select datum, category, iznos
from gk
where datum between #B_Date AND #E_Date
) as src
pivot (
sum(src.iznos)
for src.category in ([1], [2], [3])
) as pvt
This doesn't have the exact same effect as the Firebird stored procedure though, because that is returning a row for each row in gk. If you want to have the exact same result, you may have to join gk to the above query.
If you intend to use this stored procedure in a select (which is possible in Firebird, but not in SQL Server), then you need to convert it to a table-valued user-defined function.
You could also create a view instead. In that case the where clause would need to be removed.
Small example in TSQL:
create table #example (
datum date,
category int,
val int
);
insert into #example(datum, category, val) values
('2015-07-24', 1, 1),
('2015-07-24', 2, 1),
('2015-07-24', 3, 1),
('2015-07-24', 1, 1),
('2015-07-24', 2, 1),
('2015-07-25', 3, 1);
select datum, [1] as Value1, [2] as Value2, [3] as Value3
from (
select datum, category, val
from #example
) as src
pivot (
sum(src.val)
for src.category in ([1], [2], [3])
) as pvt;
drop table #example;