create trigger 触发器名 on 学生表
for insert
as
if exists(select 1 from inserted where 班级名 not in (select 班级名 from 班级表))
rollback
for insert
as
if exists(select 1 from inserted where 班级名 not in (select 班级名 from 班级表))
rollback
FOR INSERT
AS
if not exists(select 1 from 班级表 where where 班级名 in (select 班级名 from inserted))
rollback tran
INSTEAD OF insert
as
if not exists(select 1 from inserted where 班级名 not in (select 班级名 from 班级表))
插入记录
for insert
as
if exists(select 1 from inserted where 班级名 not in (select 班级名 from 班级表))
rollback我也记得好象回答过的
for insert
as
if exists(select 1 from inserted where 班级名 not in(select 班级名 from 班级表))
rollback tran
go
CREATE TRIGGER [T1] ON 学生表
for insert
as
if exists(select 1 from inserted a left join 班级表 b on a.班级名=b.班级名 where b.班级名 is null)
rollback tran
go