mysql建表: 主键,外键约束

CREATE DATABASE db_studentinfo;
USE  db_studentinfo ;

DROP TABLE IF EXISTS  t_student ;
CREATE TABLE  t_student(
   studentId  varchar(40) NOT NULL,
   stuNo  varchar(20) DEFAULT NULL,
   stuName  varchar(20) DEFAULT NULL,
   stuSex  varchar(10) DEFAULT NULL,
   stuBirthday  date DEFAULT NULL,
   stuRxsj  date DEFAULT NULL,
   stuNation  varchar(20) DEFAULT NULL,
   stuZzmm  varchar(20) DEFAULT NULL,
   classId  int(11) DEFAULT NULL,
   stuDesc  text,
   stuPic  varchar(20) DEFAULT NULL,
   PRIMARY KEY ( studentId )
) ENGINE=InnoDB DEFAULT CHARSET=utf8;

DROP TABLE IF EXISTS  t_class ;
CREATE TABLE  t_class(
   classId  int(11) NOT NULL AUTO_INCREMENT,
   className  varchar(20) DEFAULT NULL,
   gradeId  int(11) DEFAULT NULL,
   classDesc  text,
  PRIMARY KEY ( classId )
) ENGINE=InnoDB AUTO_INCREMENT=8 DEFAULT CHARSET=utf8;

DROP TABLE IF EXISTS  t_grade ;
CREATE TABLE  t_grade(
   gradeId  int(11) NOT NULL AUTO_INCREMENT,
   gradeName  varchar(20) DEFAULT NULL,
   gradeDesc  text,
   PRIMARY KEY(gradeId)
) ENGINE=InnoDB AUTO_INCREMENT=4 DEFAULT CHARSET=utf8;

insert  into  t_student(studentId , stuNo , stuName , stuSex , stuBirthday , stuRxsj , stuNation , stuZzmm , classId , stuDesc , stuPic ) values ('10bea402-23e4-4066-a4fd-534c3798a7d7','0011','美女111','男','2014-05-16','2014-06-08','回族','共青团员',5,'美女12222222','20140712081542.jpg'),('13','21',NULL,NULL,NULL,NULL,NULL,NULL,4,NULL,NULL),('14','21',NULL,NULL,NULL,NULL,NULL,NULL,4,NULL,NULL),('15','2',NULL,NULL,NULL,NULL,NULL,NULL,4,NULL,NULL),('17','2',NULL,NULL,NULL,NULL,NULL,NULL,4,NULL,NULL),('18','2',NULL,NULL,NULL,NULL,NULL,NULL,4,NULL,NULL),('19','小三','21','女','2014-05-14','2014-05-14','汉族','中共党员',5,'是','20140502030158.jpg'),('4','11','212','男','2014-04-08','2014-04-05','蒙古族','中共预备党员',4,'21','20140429052236.JPG'),('5','11','21','男','2014-04-08','2014-04-05','蒙古族','中共预备党员',4,'21','20140429052433.JPG'),('6','21','2','男','2014-04-08','2014-04-05','蒙古族',NULL,4,NULL,NULL),('7fac0234-59ef-46ea-981a-de50d24741b2','000','11','男','2014-07-10','2014-07-09','汉族','中共党员',4,'测试图片','20140710090403.jpg'),('a1cf592d-d9d4-4de1-b8ff-0db7e9852411','sss22','ss2','女','2014-05-08','2014-05-10','蒙古族','共青团员',3,'大2','20140508022528.jpg'),('a8a1816b-f24c-4fb9-b160-c8c107c80acf','21','321','男','2014-05-13','2014-05-15','蒙古族','民革党员',3,'123','20140508020709.jpg'),('b53b0b8a-7f1c-4254-8cff-e8353902f012','121','21','男','2014-07-09','2014-07-16','汉族','中共党员',3,'21','');
insert  into  t_class ( classId , className , gradeId , classDesc ) values (3,'09计本',2,'22'),(4,'08计本',1,'111'),(5,'08网本',1,'222'),(6,'10网本',3,'22'),(7,'10计本',3,'10年级计算机本科');
insert  into  t_grade(gradeId , gradeName , gradeDesc) values (1,'08级','111'),(2,'09级','222'),(3,'10级','33');

DROP TABLE IF EXISTS  t_datadic ;

CREATE TABLE t_datadic(
   ddId  int(11) NOT NULL AUTO_INCREMENT,
   ddTypeId  int(11) DEFAULT NULL,
   ddValue  varchar(20) DEFAULT NULL,
   ddDesc  text,
  PRIMARY KEY ( ddId )
) ENGINE=InnoDB AUTO_INCREMENT=343 DEFAULT CHARSET=utf8;

DROP TABLE IF EXISTS  t_datadictype ;

CREATE TABLE  t_datadictype(
   ddTypeId  int(11) NOT NULL AUTO_INCREMENT,
   ddTypeName  varchar(20) DEFAULT NULL,
   ddTypeDesc  text,
  PRIMARY KEY(ddTypeId)
) ENGINE=InnoDB AUTO_INCREMENT=4 DEFAULT CHARSET=utf8;

insert  into  t_datadic( ddId , ddTypeId , ddValue , ddDesc ) values (1,1,'男','1'),(2,1,'女',NULL),(3,2,'中共党员',NULL),(4,2,'中共预备党员',NULL),(5,2,'共青团员',NULL),(6,2,'民革党员',NULL),(7,2,'民盟盟员',NULL),(8,2,'民建会员',NULL),(9,2,'民进会员',NULL),(10,2,'农工党党员',NULL),(11,2,'致公党党员',NULL),(12,2,'九三学社社员',NULL),(13,2,'台盟盟员',NULL),(14,2,'无党派人士',NULL),(15,2,'普通公民',NULL),(16,2,'港澳同胞',NULL),(17,2,'叛徒',NULL),(18,2,'反革命分子',NULL),(334,3,'汉族',NULL),(335,3,'蒙古族',NULL),(336,3,'回族',NULL),(337,3,'藏族',NULL),(338,3,'维吾尔族',NULL),(339,3,'门巴族',NULL),(340,3,'外国血统',NULL),(342,3,'哈哈族','11');
insert  into  t_datadictype( ddTypeId , ddTypeName , ddTypeDesc ) values (1,'性别','121'),(2,'政治面貌',NULL),(3,'名族',NULL);

DROP TABLE IF EXISTS  t_user ;

CREATE TABLE  t_user(
   userId  int(11) NOT NULL AUTO_INCREMENT,
   userName  varchar(20) DEFAULT NULL,
   password  varchar(20) DEFAULT NULL,
  PRIMARY KEY ( userId )
) ENGINE=InnoDB AUTO_INCREMENT=2 DEFAULT CHARSET=utf8;
insert  into  t_user( userId , userName , password ) values (1,'java1234','12');

alter table t_student add constraint FK_t_student foreign key(classId) REFERENCES  t_class  ( classId );
alter table t_class add constraint FK_t_class foreign key(gradeId) REFERENCES t_grade(gradeId);
alter table t_datadic add constraint FK_t_datadic foreign key(ddTypeId) REFERENCES  t_datadictype  (ddTypeId);