sql 触发器 红色部分
create trigger emp on employees
for insert,update
as
begin
if( select empid from emp where exists (select empid from emp))
else
print ('员工号不存在')
end
create trigger YGGL
on table
as
begin
if (drop from table)
rollback
print("不能删除表")
end
我的回答只能是参考,触发器我很少接触,不好意思