update and case clause

[liviusbr]

Hello!I need to update the column SALARIU as follows :

If the number of nume_sectie is 1 then it wil remain unchanged
If the number of nume_sectie is 2 then it will be multiplied by 1.01
If the number of nume_sectie is more than 3 it will be multiplied by 1.03

I have the following script,so that all i have to do is replacing select clause with UPDATE

select SALARIU,nume_profesor,
(case count(nume_sectie)
when 1 then SALARIU
when 2 then SALARIU*1.01
else salariu*1.03
end) noul_salariu
from tbl_profesor,tbl_catedra,tbl_sectie
where tbl_profesor.CATEDRA=tbl_Catedra.cod_catedra
and tbl_catedra.COD_CATEDRA=tbl_sectie.COD_CATEDRA
group by salariu,nume_profesor

The tables are as follows :

select * from tbl_sectie
COD_SECTIE NUME_SECTIE COD_CATEDRA
---------- --------------- -----------
111 cts 1
222 opto 2
333 automatizari 3
444 ifia 4
555 hifi 5
5 rows selected

select * from tbl_profesor
NUME_PROFESOR DISCIPLINA SEX CATEDRA LEGITIMATIE_PROFESOR SA
-------------------- -------------------- --- ---------- -------------------- --
Stancescu RF m 1 4200
Banica CD m 1 1000
Burileanu AMP m 2 2000
Stanciu PNS m 1 3000
Luca mate f 4 600
Mateescu SCS f 3 4000
6 rows selected

select * from tbl_catedra
COD_CATEDRA NUME_CATEDRA NR_LEGSEFC COD_FACULTATE
----------- -------------------- ---------- -------------
1 Comm 2
2 electr 2
3 calc 1
4 masini 4
5 antene 3
5 rows selected