数据库实验三(2)

ALTER TABLE COURSE

ADD CONSTRAINT PK_COURSE PRIMARY KEY (COURSENO);

ALTER TABLE DEPARTMENT

ADD CONSTRAINT PK_DEPARTMENT PRIMARY KEY (DEPNO);

ALTER TABLE EMPCOURSE

ADD CONSTRAINT PK_EMCOURSE PRIMARY KEY (EMPNO,COURSENO);

创建关系：

ALTER TABLE JOBHISTORY

ADD CONSTRAINT FK_JOBHISTORY_EMPLOYEE FOREIGN KEY (EMPNO)

REFERENCES EMPLOYEE (EMPNO);

ALTER TABLE EMPCOURSE

ADD CONSTRAINT FK_EMPCOURSE_EMPLOYEE FOREIGN KEY (EMPNO)

REFERENCES EMPLOYEE (EMPNO);

ALTER TABLE EMPCOURSE

ADD CONSTRAINT FK_EMPCOURSE_COURSE FOREIGN KEY (COURSENO)

REFERENCES COURSE (COURSENO);

ALTER TABLE EMPLOYEE

ADD CONSTRAINT FK_EMPLOYEE_DEPARTMENT FOREIGN KEY (DEPNO)

REFERENCES DEPARTMENT (DEPNO);

ALTER TABLE DEPARTMENT

ADD CONSTRAINT FK_DEPARTMENT_EMPLOYEE FOREIGN KEY (HEAD)

REFERENCES EMPLOYEE(EMPNO);

具体关系：

EXECUTE sp_helpconstraint DEPARTMENT;

EXECUTE sp_helpconstraint EMPCOURSE;

EXECUTE sp_helpconstraint JOBHISTORY;

EXECUTE sp_helpconstraint EMPLOYEE;

(所有JOBS中表的约束图。注意：必须如上图所示清楚完整显示约束的constraint_type、constraint_name、constraint_keys等信息。)

4．备份JOBS数据库