I’m going to assume it’s wan
A. should be the answer hope this helps :)
Answer:
The trigger code is given below
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
Answer:
<u>First generation are</u>
a)they are unreliable
b)they are very costly and
c)huge in size
<u>Second generation are</u>
a)they use a transistor
b)smaller in size compared to first generation
c)they are faster than the first generation
<u>Third generation are </u>
a)its more reliable than the first generation and the second generation
b)faster than first generation and the second generation
c)consume less electricity
<u>Fourth generation are</u>
a) they are very cheap
b)they are very small in size
c)they are portable and reliable
Explanation:
explanation is in the answer
