领域建模

• 阅读 Asg_RH 文档，按用例构建领域模型

  task2

• 数据库建模(E-R 模型)

  physicalmodel

  导出的 MySQL 脚本：

  drop table if exists Hotel;
  
  drop table if exists "Order";
  
  drop table if exists Room;
  
  drop table if exists User;
  
  /*==============================================================*/
  /* Table: Hotel                                                 */
  /*==============================================================*/
  create table Hotel
  (
     hotelID              integer not null,
     roomID               Integer,
     city                 char not null,
     name                 char not null,
     primary key (hotelID)
  );
  
  /*==============================================================*/
  /* Table: "Order"                                               */
  /*==============================================================*/
  create table "Order"
  (
     indateTime           datetime not null,
     outdateTime          datetime not null,
     hotelID              integer not null,
     roomType             char not null,
     orderID              integer not null,
     userID               char(20),
     primary key (orderID)
  );
  
  /*==============================================================*/
  /* Table: Room                                                  */
  /*==============================================================*/
  create table Room
  (
     roomID               Integer not null,
     type                 varchar(20) not null,
     price                integer not null,
     hotelID              integer not null,
     primary key (roomID)
  );
  
  /*==============================================================*/
  /* Table: User                                                  */
  /*==============================================================*/
  create table User
  (
     userID               char(20) not null,
     orderID              integer,
     name                 char(20) not null,
     phone                integer(11) not null,
     email                char(30) not null,
     primary key (userID)
  );
  
  alter table Hotel add constraint FK_Reference_2 foreign key (roomID)
        references Room (roomID) on delete restrict on update restrict;
  
  alter table "Order" add constraint FK_Reference_1 foreign key (hotelID)
        references Hotel (hotelID) on delete restrict on update restrict;
  
  alter table "Order" add constraint FK_Reference_4 foreign key ()
        references User (userID) on delete restrict on update restrict;
  
  alter table "Order" add constraint FK_Reference_5 foreign key ()
        references User (userID) on delete restrict on update restrict;
  
  alter table "Order" add constraint FK_Reference_6 foreign key (userID)
        references User (userID) on delete restrict on update restrict;
  
  alter table User add constraint FK_Reference_3 foreign key (orderID)
        references "Order" (orderID) on delete restrict on update restrict;
  
  

• 数据库逻辑模型 与 领域模型 的异同

1. 相同：都是用来抽象出主要的类，描述不同类之间的关系，从而辅助分析与设计

2. 不同处：领域模型是对用户业务的领域描述的高度抽象，可以帮助需求分析人员快速熟悉目标领域的词汇和操作，从而更好的理解业务需求；不涉及到具体的实现。但数据库逻辑模型涉及到数据库的具体实现，对象是实体和关系（ER），描述了具体的实现方法。

   用户只需要关心领域模型，开发人员通过领域模型的描述，构建数据库逻辑模型。