下面是sql server中创建数据库，创建数据表以及添加约束的sql语句：
use master
--创建数据库
if exists (select * from sysdatabases where name = 'jobtest')
drop database jobtest
create database jobtest
on
(
name='jobtest_data',
filename = 'D:\DB\jobtest_data.mdf',
size = 10MB,
filegrowth = 10%
)
log on
(
name = 'jobtest_log',
filename = 'D:\DB\jobtest_log.ldf',
size = 10MB,
maxsize = 20MB,
filegrowth = 1MB
)
go
--创建student表
if exists (select * from sysobjects where name = 'student')
drop table student
create table student
(
id int not null,
name varchar(50) not null,
age int not null
)
go
--创建grade表
if exists (select * from sysobjects where name = 'grade')
drop table grade
create table grade
(
id int not null,
gname varchar(50) not null
)
--添加约束
--主键
alter table student
add constraint pksid primary key (id)
--唯一约束
alter table student
add constraint ukid unique(id)
--默认约束
alter table student
add constraint df_name default('张三') for name
--检查约束
alter table student
add constraint ck_age check (age>0 and age<100)
--必须给另一个表添加主键
alter table grade
add constraint pkid primary key (id)
--外键约束
alter table student
add constraint fkgid foreign key (id) references grade (id) 
