SQL 문의 함수

create function fun1(@sno char(10)) returns int 
as
begin
	declare @res int 
	select @res = sum(credit) from student s
	inner join sc on sc.sno = sc.sno
	inner join course c on c.cno = sc.cno
	where s.sno = @sno and grade > 60
	return @res
end

create function fun2(@sdept char(10),@cno char(10)) returns int 
as
begin
	declare @res int
	select @res=avg(grade) from student s
	inner join sc on sc.sno = s.sno
	group by sdept,cno
	having sdept = @sdept and cno = @cno
	return @res
end

create function fun3(@sdept char(10),@num int) returns int
as
begin
	declare @res int
	select @res = count(*) from student s
	inner join sc on sc.sno = s.sno
	where ssex = ' ' and sdept = @sdept
	group by s.sno
	having count(*) > @num
return @res
end