以下是sqlserver的代码
create trigger emp_delete on person
for delete
as
begin
update department set department.num =(select COUNT(cno) from person where department.sname=personnel.sname)
where department.sname in (select department.sname from deleted)
end
create trigger emp_insert on person
for insert
as
begin
update department set department.num=(select COUNT(cno) from person where department.sname =person.sname)
where department.sname in (select department.sname from inserted)
end
以上是sqlserver语句．求改成mysql的，谢谢！！