SQL语句创建数据库 表 关系

use master
if exists (select * from sysdatabase where name ='MySchool')    --判断数据库是否存在
drop database MySchool                                                            --删除数据库
create database MySchool                                                         --创建数据库
on
(
name = 'MySchool_data',                                                        --数据库名称
filename='D:\数据库\MySchool_data.mdf',                               --数据库路径
size=5MB ,                                                                               --文件初始大小
maxsize=100MB,                                                                      --文件最大值
filegrowth=15%                                                                        --文件增长率
)
Log on
(
name = 'MySchool_log',
filename='D:\数据库\MySchool_log.ldf',
size=5MB ,
filegrowth=1MB
)
go
if exists (select * from sysobjects where  name='Grade')               --判断表是否存在
drop table Grade                                                                           --删除表
create table Grade                                                                        --创建表
(
grade_id     int     not null,
grade_name     nvarchar(50)     not null
)
go
if esists(select * from sysobjects where name = 'Student')
drop table student
create table Student
(
StudentNo     int     not null,
StudentName    nvarrchar(50)     not null,
LoginPwd    nvarchar(50)    not null,
GradeId    int    not null,
BornDate    datetime    not null,
Address    nvarchar(50)    not null,
IDCard    nvarchar(50)    not null
)
go
alter table Grade                                                                                     --主键约束
add constraint PK_grade_id primary  key(grade_id)
alter table Student                                                                                    --主键约束
add constraint PK_StudentNo primary key (StudentNo)
alter table Student                                                                                     --默认约束
add constraint DF_LoginPwd default ('123456') for LoginPwd
alter table Student                                                                                      --唯一约束
add constraint UQ_IDCard unique(IDCard)
alter table Student                                                                                     --检查约束
add constraint CK_BornDate check(BornDate>='1980-01-01')
alter table Student                                                                                      --外键约束
add constraint FK_StudentNo foreign key(GradeId)  references Grade(grade_id)

以后不记得了就可以来看看

<pre name="code" class="plain"><strong><span style="font-size:24px;">JQuery EasyUI 新开QQ交流群 511830793</span></strong>

<strong><span style="font-size:24px;">
欢迎大家前来与我一起学习，共同进步！</span></strong>

</pre><pre name="code" class="sql">