数据库作业-一个简单的火车购买系统库
设计一个火车订票系统数据库，记录乘客的购票情况，其中乘客有Cid，Cname，Tel，各属性分别表示客户身份证号,客户姓名，客户电话；火车班次有Tno，Start，End，各属性分别表示火车班次号，始发地，目的地；乘客在购买车票的时候要记录价格，时间，座位等级信息。
•根据以上信息完成数据库的设计（要求CDM、PDM、sql代码、数据库生成结果截图）
首先使用powerdesigner生成cdm图
使用cdm生成pdm图
需要在购买那个关系增加一些属性
连接数据库 生成sql代码
/*==============================================================*/
/* DBMS name: Microsoft SQL Server 2017 */
/* Created on: 2022/4/26 15:01:22 */
/*==============================================================*/
if exists (select 1
from sys.sysreferences r join sys.sysobjects o on (o.id = r.constid and o.type = 'F')
where r.fkeyid = object_id('购买') and o.name = 'FK_购买_购买_乘客')
alter table 购买
drop constraint FK_购买_购买_乘客
go
if exists (select 1
from sys.sysreferences r join sys.sysobjects o on (o.id = r.constid and o.type = 'F')
where r.fkeyid = object_id('购买') and o.name = 'FK_购买_购买2_火车班次')
alter table 购买
drop constraint FK_购买_购买2_火车班次
go
if exists (select 1
from sysobjects
where id = object_id('乘客')
and type = 'U')
drop table 乘客
go
if exists (select 1
from sysobjects
where id = object_id('火车班次')
and type = 'U')
drop table 火车班次
go
if exists (select 1
from sysindexes
where id = object_id('购买')
and name = '购买2_FK'
and indid > 0
and indid < 255)
drop index 购买.购买2_FK
go
if exists (select 1
from sysindexes
where id = object_id('购买')
and name = '购买_FK'
and indid > 0
and indid < 255)
drop index 购买.购买_FK
go
if exists (select 1
from sysobjects
where id = object_id('购买')
and type = 'U')
drop table 购买
go
/*==============================================================*/
/* Table: 乘客 */
/*==============================================================*/
create table 乘客 (
cid char(18) not null,
cname char(10) null,
tel char(11) null,
constraint PK_乘客 primary key (cid)
)
go
/*==============================================================*/
/* Table: 火车班次 */
/*==============================================================*/
create table 火车班次 (
tno char(10) not null,
start char(20) null,
"end" char(20) null,
constraint PK_火车班次 primary key (tno)
)
go
/*==============================================================*/
/* Table: 购买 */
/*==============================================================*/
create table 购买 (
cid char(18) not null,
tno char(10) not null,
价格 float null,
时间 datetime null,
座位等级 char(1) null,
constraint PK_购买 primary key (cid, tno)
)
go
/*==============================================================*/
/* Index: 购买_FK */
/*==============================================================*/
create nonclustered index 购买_FK on 购买 (cid ASC)
go
/*==============================================================*/
/* Index: 购买2_FK */
/*==============================================================*/
create nonclustered index 购买2_FK on 购买 (tno ASC)
go
alter table 购买
add constraint FK_购买_购买_乘客 foreign key (cid)
references 乘客 (cid)
go
alter table 购买
add constraint FK_购买_购买2_火车班次 foreign key (tno)
references 火车班次 (tno)
go
测试代码：
create database test;
select * from 火车班次;
select * from 乘客;
select * from 购买;
insert into 乘客 values('001','张三','123456789');
insert into 乘客 values('002','李四','123454389');
insert into 乘客 values('003','沈五','987654321');
insert into 火车班次 values('t001','北京','重庆');
insert into 火车班次 values('t002','上海','重庆');
insert into 火车班次 values('t003','广东','重庆');
insert into 购买 values('001','t001','100','2022-4-26','A');
insert into 购买 values('001','t002','100','2022-4-26','A');
insert into 购买 values('002','t003','100','2022-4-26','B');
insert into 购买 values('003','t002','100','2022-4-26','C');
select * from 购买 join 火车班次 on 购买.tno=火车班次.tno
join 乘客 on 乘客.cid=购买.cid;