PowerDesigner中PDM导出的SQL语句

/*==============================================================*/
/* DBMS name:      MySQL 5.0                                    */
/* Created on:     2014/11/23 2:03:17                           */
/*==============================================================*/


drop table if exists Class;

drop table if exists Course;

drop table if exists Student;

drop table if exists 选课;

/*==============================================================*/
/* Table: Class                                                 */
/*==============================================================*/
create table Class
(
   班级号                  char(4) not null,
   Sno                  char(12),
   班级名                  varchar(20),
   primary key (班级号)
);

/*==============================================================*/
/* Table: Course                                                */
/*==============================================================*/
create table Course
(
   Cno                  char(4) not null,
   Cname                char(10),
   Ccredit              int,
   Cpno                 char(4),
   primary key (Cno)
);

/*==============================================================*/
/* Table: Student                                               */
/*==============================================================*/
create table Student
(
   Sno                  char(12) not null,
   班级号                  char(4),
   Sname                varchar(10) not null,
   Ssex                 char(2),
   Sage                 int,
   primary key (Sno)
);

/*==============================================================*/
/* Table: 选课                                                    */
/*==============================================================*/
create table 选课
(
   Cno                  char(4) not null,
   Sno                  char(12) not null,
   成绩                   int,
   primary key (Cno, Sno)
);

alter table Class add constraint FK_任班长 foreign key (Sno)
      references Student (Sno) on delete restrict on update restrict;

alter table Student add constraint FK_属于 foreign key (班级号)
      references Class (班级号) on delete restrict on update restrict;

alter table 选课 add constraint FK_选课 foreign key (Cno)
      references Course (Cno) on delete restrict on update restrict;

alter table 选课 add constraint FK_选课2 foreign key (Sno)
      references Student (Sno) on delete restrict on update restrict;