Answer:
so i research and found this,
Development is when findings of a research are utilized for the production of specific products including materials, systems and methods. Design and development of prototypes and processes are also part of this area. Engineering is utilization of these plans and research to produce commercial products.
Answer:
modulator
Explanation:
A modulator is a device that performs modulation.
(Single conversation)
Answer:
create trigger F1_Del
after delete on Friend
for each row
when exists (select * from Friend
where ID1 = Old.ID2 and ID2 = Old.ID1)
begin
delete from Friend
where (ID1 = Old.ID2 and ID2 = Old.ID1);
end
create trigger F1_Insert
after insert on Friend
for each row
when not exists (select * from Friend
where ID1 = New.ID2 and ID2 = New.ID1)
begin
insert into Friend values (New.ID2, New.ID1);
end
