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/*
创建两表,建立一个视图基于这两张表。
创建触发器实现向视图插入数据时等于
分别向两表插入数据
*/
--创建表tbl_dept:
create table tbl_dept(
deptid varchar(4) primary key,
deptname varchar(10) not null
)
--创建表tbl_emp:
create table tbl_emp(
empid varchar(10) primary key,
empname varchar(20) not null,
deptid varchar(4) foreign key
references tbl_dept(deptid)
not null
)
--创建视图用于存储表tbl_dept和tbl_emp表中的数据:
create view v_empinfo
as
select
tbl_emp.empid,tbl_emp.empname,tbl_emp.deptid,
tbl_dept.deptname
from
tbl_emp,tbl_dept
where
tbl_emp.deptid=tbl_dept.deptid
select *from v_empinfo
--创建触发器实现上述功能:
create trigger tr_insert on v_empinfo
instead of insert
as
declare @eid varchar(10),@ename varchar(20),
@did varchar(4),@dname varchar(10)
select @eid=empid,@ename=empname,
@did=deptid,@dname=deptname
from
inserted
insert into tbl_dept values(@did,@dname)
insert into tbl_emp values(@eid,@ename,@did)
--验证是否成功向两表中插入数据:
insert into v_empinfo values('200911076','tracy',
'1001','sales')
select *from tbl_emp
select *from tbl_dept
--创建触发器实现删除主表中的数据时自动删除附表中的数据:
--创建表tbl_stu:
create table tbl_stu(
stuid varchar(15) primary key,
stuname varchar(20) not null
)
--插入数据:
insert into tbl_stu values('200911076','李白和')
insert into tbl_stu values('200911077','王洪洋')
--创建表tbl_score:
create table tbl_score(
stuid varchar(15)
foreign key
references tbl_stu(stuid)
not null,
Math int default(0)
)
--插入数据:
insert into tbl_score values('200911076',85)
insert into tbl_score values('200911077',95)
--创建视图v_view:
create view v_view
as
select
s.stuid,s.stuname,sc.math
from
tbl_stu s,tbl_score sc
where
s.stuid=sc.stuid
--为视图创建触发器tr_delete:
create trigger tr_delete on v_view
instead of delete
as
declare @stuid varchar(15),@stuname varchar(20),
@math int
select @stuid=stuid,@stuname=stuname,@math=math
from deleted
delete tbl_score where stuid=@stuid
delete tbl_stu where stuid=@stuid
--验证是否删除两表中对应的所有信息
delete v_view where stuid='200911077'
select *from tbl_stu
select *from tbl_score
曾经学习时的例子,上机练习
create trigger my_trig on A for insert
as
begin
insert into b (需要的字段) select 需要的字段或数据值 from inserted
end