use master
go
IF exists(
select
1
from
sysdatabases
where
name=
'temp'
)
BEGIN
DROP DATABASE temp
END
create database temp
go
use temp
go
--drop table ProductInfo
create table ProductInfo
(
ProductId
int
primary key ,
ProductName varchar(20),
)
create table ProductDetails
(
id
int
identity(1,1) primary key,
num varchar(100) ,
ProductId
int
,
foreign key (ProductId) references ProductInfo(ProductId)
on
delete cascade
on
update cascade
)
insert ProductInfo values (1,
'Think'
)
insert ProductInfo values(2,
'TCL'
)
insert ProductInfo values(3,
'HTC'
)
insert ProductDetails values(
'T420'
,1)
insert ProductDetails values(
'Xo1'
,1)
insert ProductDetails values(
'TVoo1'
,2)
insert ProductDetails values(
'TPhone'
,2)
insert ProductDetails values(
'One'
,3)
insert ProductDetails values(
'Buffer'
,3)
alter table 表名
add constraint 外键名
foreign key(字段名) references 主表名(字段名)
on
delete cascade --删除
on
update cascade --更新
--查看现有数据
select
*
from
ProductInfo
select
*
from
ProductDetails
--更改
update ProductInfo
set
ProductId=5
where
ProductName=
'Think'
select
*
from
ProductInfo
select
*
from
ProductDetails
--删除
delete
from
ProductInfo
where
ProductId=5
select
*
from
ProductInfo
select
*
from
ProductDetails