tomar un campo del reguistro siguiente

[flaviovich]

Podria ser algo asi:

Código:

create function fn_cantidad
(
    @cod_prod int,
    @cant_ped int
)
returns int
as

declare @cantidad int
declare @sum_cant int

declare cur_cant cursor for
    select cantidad
    from tabla
    where cod_prod = @cod_prod
for read only

open cur_cant
fetch next from cur_cant into @cantidad

set @sum_cant = cantidad
while @@fetch_status = 0
begin
    if @sum_cant >= @cant_ped
    begin
        /* Todo OK */
        return @cant_ped
    end
    fetch next from cur_cant into @cantidad
    set @sum_cant = @sum_cant + @cantidad
end

close cur_cant
deallocate cur_cant