sql2005 如何用语句实现级联删除?

/*标题：两表通过字段关联进行级联删除。作者：爱新觉罗·毓华(十八年风雨,守得冰山雪莲花开) 时间：2008-11-20地点：广东深圳*/create table ta(id int not null)create table tb(id int , aid int)insert into ta values(1)insert into ta values(2)insert into tb values(1 , 1)insert into tb values(2 , 2)insert into tb values(3 , 1)go--一、查看原始数据--ta表的原始数据select * from ta/*id          ----------- 12*/--tb表的原始数据select * from tb/*id          aid         ----------- ----------- 1           12           23           1*/--二、看看没有创建级联删除时的情况(删除ta表id=1的数据,看看是否影响tb表)delete from ta where id = 1select * from ta/*id          ----------- 2*/select * from tb/*id          aid         ----------- ----------- 1           12           23           1*/--三、恢复原始数据，创建级联删除,删除ta表id=1的数据,看看是否影响tb表insert into ta values(1)--为ta创建主健alter table ta add constraint pk_ta_id primary key (id)go--为tb创建外健，并指定级联删除alter table tb add constraint fk_tb_aid foreign key (aid) references ta(id) on delete cascadegodelete from ta where id = 1select * from ta/*id          ----------- 2*/select * from tb/*id          aid         ----------- ----------- 2           2*/--删除级联约束alter table tb drop constraint fk_tb_aidgo--删除测试表drop table ta , tbgo