系统分析与设计（五）

系统分析与设计（五）

• a. 阅读 Asg_RH 文档，

  按用例

  构建领域模型。

  • 按 Task2 要求，请使用工具 UMLet，截图格式务必是 png 并控制尺寸
  • 说明：请不要受 PCMEF 层次结构影响。你需要识别实体（E）和 中介实体（M，也称状态实体）
  • 在单页面应用（如 vue）中，E 一般与数据库构建有关， M 一般与 store 模式 有关
  • 在 java web 应用中，E 一般与数据库构建有关， M 一般与 session 有关

• b. 数据库建模(E-R 模型)
  - 按 Task 3 要求，给出系统的 E-R 模型（数据逻辑模型）
  - 建模工具 PowerDesigner（简称PD） 或开源工具 OpenSystemArchitect
  - 不负责的链接 http://www.cnblogs.com/mcgrady/archive/2013/05/25/3098588.html
  - 导出 Mysql 物理数据库的脚本
  - 简单叙说 数据库逻辑模型 与 领域模型 的异同

a. 构建领域模型

Find Hotel用例的领域模型图：

Make Reservation用例的领域模型图：

Pay用例的领域模型图：

b. 数据库建模(E-R 模型)

/*==============================================================*/
/* DBMS name:      MySQL 5.0                                    */
/* Created on:     2018/4/28 22:34:28                           */
/*==============================================================*/


drop table if exists Bill;

drop table if exists Credit_Card;

drop table if exists Hotel;

drop table if exists Reservation;

drop table if exists Room;

drop table if exists Traveler;

/*==============================================================*/
/* Table: Bill                                                  */
/*==============================================================*/
create table Bill
(
   Price                double,
   Email                text,
   Card_Number          text,
   Bill_Number          text not null,
   Reservation_Number   text not null,
   primary key (Bill_Number)
);

/*==============================================================*/
/* Table: Credit_Card                                           */
/*==============================================================*/
create table Credit_Card
(
   Card_Number          text not null,
   Owner                text,
   Saving               double,
   Security_Code        text,
   primary key (Card_Number)
);

/*==============================================================*/
/* Table: Hotel                                                 */
/*==============================================================*/
create table Hotel
(
   Hotel_Name           text not null,
   City                 text,
   Address              text not null,
   primary key (Hotel_Name, Address)
);

/*==============================================================*/
/* Table: Reservation                                           */
/*==============================================================*/
create table Reservation
(
   Room_Number          text not null,
   Check_In             date not null,
   Check_Out            date not null,
   Hotel_Name           text not null,
   Address              text not null,
   Adult_Count          int,
   Child_Count          int,
   Child_Age            int,
   Price                double,
   Traveler_Name        text,
   Reservation_Number   text not null,
   Bill_Number          text not null,
   primary key (Reservation_Number)
);

/*==============================================================*/
/* Table: Room                                                  */
/*==============================================================*/
create table Room
(
   Room_Number          text not null,
   Hotel_Name           text,
   Address              text,
   Availability         bool,
   primary key (Room_Number)
);

/*==============================================================*/
/* Table: Traveler                                              */
/*==============================================================*/
create table Traveler
(
   Name                 text,
   Email                text not null,
   Smoking              bool,
   primary key (Email)
);

alter table Bill add constraint FK_Reference_3 foreign key (Email)
      references Traveler (Email) on delete restrict on update restrict;

alter table Bill add constraint FK_Reference_4 foreign key (Card_Number)
      references Credit_Card (Card_Number) on delete restrict on update restrict;

alter table Bill add constraint FK_Reference_6 foreign key (Reservation_Number)
      references Reservation (Reservation_Number) on delete restrict on update restrict;

alter table Reservation add constraint FK_Reference_1 foreign key (Room_Number)
      references Room (Room_Number) on delete restrict on update restrict;

alter table Reservation add constraint FK_Reference_5 foreign key (Hotel_Name, Address)
      references Hotel (Hotel_Name, Address) on delete restrict on update restrict;

alter table Reservation add constraint FK_Reference_6 foreign key (Bill_Number)
      references Bill (Bill_Number) on delete restrict on update restrict;

alter table Room add constraint FK_Reference_2 foreign key (Hotel_Name, Address)
      references Hotel (Hotel_Name, Address) on delete restrict on update restrict;

数据库逻辑模型与领域模型的异同：都常用于系统分析与设计，特别是涉及数据表的设计。不同之处在于，领域模型偏向概念，设计者无需考虑系统内数据的具体存放方式，而更需考虑如何结合系统用例以满足用户需求。数据库逻辑模型则更适用于软件开发者，它要求对数据库有较具体的设计，比领域模型考虑更细致。