create or replace trigger dml_a
before insert or delete or update on a
for each row
as
begin
when inserting then
insert into b values(怎么写);
when deletint then
delete from b where 怎么写;
end dml_a;
...
before insert or delete or update on a
for each row
as
begin
when inserting then
insert into b values(怎么写);
when deletint then
delete from b where 怎么写;
end dml_a;
...
2. delete from b where b.id in(select id from deleted)
as
begin
if not exists(select 1 from inserted)
delete b from deleted d where b.关键字 = d.关键字
else if not exists(select 1 from deleted)
insert into b select * from inserted
else
update b set .... from inserted t where b.关键字 = t.关键字
end