set serveroutput on
Accept m prompt 'foglalkozas'

Declare
function atlag(fogl in varchar) return number
is
eredm number;
begin
select avg(sal) into eredm from emp where job=fogl;
return eredm;
end;
begin
dbms_output.put_line('&m foglalkozas atlagfizetese: '||atlag('&m'));
end;
/




-- --------------------------------------------------------------------


Declare
m Number; --faktorialis
Function f(x Number) Return Number
Is
  Begin
	IF x=0 THEN RETURN 1;
	END IF;
	RETURN x*f(x-1);
  End;
Begin
  m:=&n;
  dbms_output.put_line(to_char(m)||'!='||f(m));
End;
/

-- ---------------------------------------------------------------------

-- osszeg szamitas

drop function osszeg;

Create function osszeg(fogl in varchar) return number
is
	eredm number;
begin
	select sum(sal) into eredm from emp where job=fogl;
	return eredm;
end;
/
show errors



select osszeg('CLERK') from dual;