CREATE TABLE pracovnici (
ID varchar(5),
kod int,
Datum date,
suma int
);

INSERT INTO Pracovnici(ID, kod, Datum, suma) VALUES ('a',1, '20250101', 5);
INSERT INTO Pracovnici(ID, kod, Datum, suma) VALUES ('b',2, '20250101', 10);
INSERT INTO Pracovnici(ID, kod, Datum, suma) VALUES ('c',1, '20250101', 7);
INSERT INTO Pracovnici(ID, kod, Datum, suma) VALUES ('c',10, '20250101', 15);
INSERT INTO Pracovnici(ID, kod, Datum, suma) VALUES ('d', 2, '20250101', 10);
INSERT INTO Pracovnici(ID, kod, Datum, suma) VALUES ('d', 34, '20250101', 20);

-- QUERY database
select b.ID, b.Datum, b.Kod, sum(b.suma)
from pracovnici b
join (select ID, Datum, max(Kod) as max_kod
from pracovnici
group by ID, Datum
) a
where a.ID=b.ID
and a.Datum=b.Datum
and a.max_kod=b.Kod
group by b.ID, b.Datum, b.Kod;