Question

课程程序应该是：

COURSE表中已存在先决条件课程（如果有）。为简单起见我们会假装一门课程最多只能有一门课程作为先决条件。
课程的先决条件必须是较低的水平。例如，前提条件 ISYS326必须是100或200级课程，不能是300级课程。
如果上述任一要求失败，则该过程引发异常WRONG_PREREQ 打印适当的警报消息，不修改COURSE表。

所以我完成了上述程序：

create or replace PROCEDURE NEW_COURSE (
  CID   IN COURSE.COURSEID%TYPE, 
  CNAME IN COURSE.COURSENAME%TYPE,
  PID   IN HAS_PREREQUISITE.PREREQUISITEID%TYPE,
  DID   IN DEPARTMENT.DEPTID%TYPE
)
IS 
  CONDITION1 NUMBER;
  CONDITION2 NUMBER;
  WRONG_PREQ EXCEPTION;
BEGIN
  /* this can be checked before any SQL */
  IF (SUBSTR(CID,5,3) <= SUBSTR(PID,5,3)) THEN /*PREREQUISITE HAS A HIGHER ID THAN COURSEID */
    RAISE WRONG_PREQ;
  END IF;



  SELECT COUNT(COURSEID) 
    INTO CONDITION1
    FROM  COURSE 
   WHERE COURSEID = PID;

  /* this can be checked here, without running the second select */
  IF (CONDITION1 <>1)  THEN /*VIOLATION OF CONDITION 1, NO EXISTING 
                              PREREQUISITE COURSE*/
    RAISE WRONG_PREQ;
  END IF; 


  SELECT COUNT(*)
    INTO CONDITION2
    FROM HAS_PREREQUISITE
   WHERE COURSEID = CID 
     AND PREREQUISITEID = PID 
     AND SUBSTR(CID,5,3) > SUBSTR(PID,5,3);

  IF (CONDITION2 = 1) THEN /*THE RECORD ALREADYS EXISTS IN HAS_PREREQUISITE 
                             TABLE*/
    RAISE WRONG_PREQ;
  END IF;



  INSERT INTO COURSE VALUES(CID,CNAME,DID,NULL,NULL,NULL,NULL,NULL,NULL);  /* edit the statement to fit the table structure  also 'NULL' or null ?*/
  INSERT INTO HAS_PREREQUISITE VALUES(CID,PID);         /* the table only has 2 colums */
  INSERT INTO DEPARTMENT VALUES (DID,NULL,NULL,NULL);        /* edit the statement to fit the table structure. also 'NULL' or null ? */
EXCEPTION
  WHEN WRONG_PREQ THEN
    DBMS_OUTPUT.PUT_LINE('COURSEID OR PREREQUISITE ID IS INVALID');
END NEW_COURSE;

当我试图通过像这样的匿名阻止来调用该程序时

SET SERVEROUTPUT ON
DECLARE
CID char(8):='isys228';
CNAME varchar2(20):='Greendata';
PID char(8):='isys114';
DID char(8):='comp3647';
BEGIN
DBMS_OUTPUT.PUT_LINE('The course has been enrolled');
NEW_COURSE(CNAME,CID,PID,DID);
END;
/

更新：匿名块有效，但我无法看到表中输入的数据

我试图以ISYS114为先决条件，通过此程序开设一门新课程ISYS228，“绿色数据”。

请帮助!!我对这个sql相当新，所以我很难看到我出错的地方

只是抱怨ddl

/*==============================================================*/
/* DBMS name:      ORACLE Version 11g                           */
/* Created on:     11/10/2016 3:47:29 PM                        */
/*==============================================================*/


alter table ACADEMIC_REC
   drop constraint FK_ACADEMIC_RELATIONS_STUDENT;

alter table ACADEMIC_REC
   drop constraint FK_ACADEMIC_RELATIONS_COURSE;

alter table COURSE
   drop constraint FK_COURSE_OFFERS_DEPARTME;

alter table ENROLS
   drop constraint FK_ENROLS_ENROLS_STUDENT;

alter table ENROLS
   drop constraint FK_ENROLS_ENROLS2_TUT_PRAC;

alter table HAS_PREREQUISITE
   drop constraint FK_HAS_PRER_HAS_PRERE_COURSE;

alter table HAS_PREREQUISITE
   drop constraint FK_HAS_PRER_HAS_PRERE_COURSE;

alter table STAFF
   drop constraint FK_STAFF_RELATIONS_DEPARTME;

alter table TEACHING_INFORMATION
   drop constraint FK_TEACHING_RELATIONS_STAFF;

alter table TEACHING_INFORMATION
   drop constraint FK_TEACHING_RELATIONS_COURSE;

alter table TUT_PRAC
   drop constraint FK_TUT_PRAC_HAS_COURSE;

alter table TUT_PRAC
   drop constraint FK_TUT_PRAC_RELATIONS_STAFF;

drop table ACADEMIC_REC  cascade constraints;

drop table COURSE cascade constraints;

drop table ENROLS cascade constraints;

drop table HAS_PREREQUISITE cascade constraints;

drop table STAFF cascade constraints;

drop table STUDENT cascade constraints;

drop table TEACHING_INFORMATION cascade constraints;

drop table TUT_PRAC cascade constraints;

/*==============================================================*/
/* Table: ACADEMIC_REC                                          */
/*==============================================================*/
create table ACADEMIC_REC 
(
   STUID                CHAR(8)              not null,
   COURSEID             CHAR(8)              not null,
   STATUS               VARCHAR2(5),
   YEAR                 NUMBER(4),
   SEMESTER             CHAR(2),
   GRADE                VARCHAR2(2)         
      constraint CKC_GRADE_ACADEMIC check (GRADE is null or (GRADE in ('HD','D','CR','P','F'))),
   constraint PK_ACADEMIC_REC primary key (STUID, COURSEID)
);


/*==============================================================*/
/* Table: COURSE                                                */
/*==============================================================*/
create table COURSE 
(
   COURSEID             CHAR(8)              not null,
   DEPTID               CHAR(8)              not null,
   COURSENAME           VARCHAR2(20),
   TEXTBOOK             VARCHAR2(20),
   CREDITHOUR           NUMBER(2),
   MAX_ENROL            NUMBER(4),
   ACTUAL_ENROL         NUMBER(4),
   AVAILABILITY         NUMBER(4),
   COURSE_TIME          CHAR(7),
   constraint PK_COURSE primary key (COURSEID)
);


/*==============================================================*/
/* Table: DEPARTMENT                                            */
/*==============================================================*/
create table DEPARTMENT 
(
   DEPTID               CHAR(8)              not null,
   DEPTNAME             VARCHAR2(20),
   DEPTCONTACTNO        NUMBER(10),
   BUILDING             VARCHAR2(5),
   constraint PK_DEPARTMENT primary key (DEPTID)
);

/*==============================================================*/
/* Table: ENROLS                                                */
/*==============================================================*/
create table ENROLS 
(
   STUID                CHAR(8)              not null,
   CLASSID              CHAR(8)              not null,
   constraint PK_ENROLS primary key (STUID, CLASSID)
);


/*==============================================================*/
/* Table: HAS_PREREQUISITE                                      */
/*==============================================================*/
create table HAS_PREREQUISITE 
(
   COURSEID             CHAR(8)              not null,
   PREREQUISITEID       CHAR(8)              not null,
   constraint PK_HAS_PREREQUISITE primary key (COURSEID, PREREQUISITEID)
);


/*==============================================================*/
/* Table: STAFF                                                 */
/*==============================================================*/
create table STAFF 
(
   STAFFID              CHAR(8)              not null,
   DEPARTMENTID         CHAR(8)              not null,
   STAFFNAME            VARCHAR2(50),
   STAFFADDRESS         VARCHAR2(70),
   STAFFCONTACTNO       NUMBER(10),
   STAFFEMAIL           VARCHAR2(50),
   OFFICENO             NUMBER(5),
   ROLE                 VARCHAR2(10),
   constraint PK_STAFF primary key (STAFFID)
);


/*==============================================================*/
/* Table: STUDENT                                               */
/*==============================================================*/
create table STUDENT 
(
   STUID                CHAR(8)              not null,
   DEGREE               VARCHAR2(10),
   MAJOR                VARCHAR2(10),
   STU_NAME             VARCHAR2(50),
   STU_ADDRESS          VARCHAR2(70),
   CONTACTNO            NUMBER(10),
   EMAIL                VARCHAR2(50),
   constraint PK_STUDENT primary key (STUID)
);

/*==============================================================*/
/* Table: TEACHING_INFORMATION                                  */
/*==============================================================*/
create table TEACHING_INFORMATION 
(
   STAFFID              CHAR(8)              not null,
   COURSEID             CHAR(8)              not null,
   SEMESTER             CHAR(2)              not null,
   YEAR                 NUMBER(4)            not null,
   constraint PK_TEACHING_INFORMATION primary key (STAFFID, COURSEID, SEMESTER, YEAR)
);


/*==============================================================*/
/* Table: TUT_PRAC                                              */
/*==============================================================*/
create table TUT_PRAC 
(
   CLASSID              CHAR(8)              not null,
   COURSEID             CHAR(8)              not null,
   STAFFID              CHAR(8)              not null,
   TYPE                 VARCHAR2(5),
   DAY                  VARCHAR2(10),
   TIME                 DATE,
   ROOMID               CHAR(10),
   NO_OF_SEATS          NUMBER(2),
   constraint PK_TUT_PRAC primary key (CLASSID)
);


alter table ACADEMIC_REC
   add constraint FK_ACADEMIC_RELATIONS_STUDENT foreign key (STUID)
      references STUDENT (STUID);

alter table ACADEMIC_REC
   add constraint FK_ACADEMIC_RELATIONS_COURSE foreign key (COURSEID)
      references COURSE (COURSEID);

alter table COURSE
   add constraint FK_COURSE_OFFERS_DEPARTME foreign key (DEPTID)
      references DEPARTMENT (DEPTID);

alter table ENROLS
   add constraint FK_ENROLS_ENROLS_STUDENT foreign key (STUID)
      references STUDENT (STUID);

alter table ENROLS
   add constraint FK_ENROLS_ENROLS2_TUT_PRAC foreign key (CLASSID)
      references TUT_PRAC (CLASSID);

alter table HAS_PREREQUISITE
   add constraint FK_HAS_PRER_HAS_PRERE_COURSE foreign key (COURSEID)
      references COURSE (COURSEID);

alter table HAS_PREREQUISITE
   add constraint FK_HAS_PRER_HAS_PRERE_COURSE foreign key (PREREQUISITEID)
      references COURSE (COURSEID);

alter table STAFF
   add constraint FK_STAFF_RELATIONS_DEPARTME foreign key (DEPARTMENTID)
      references DEPARTMENT (DEPTID);

alter table TEACHING_INFORMATION
   add constraint FK_TEACHING_RELATIONS_STAFF foreign key (STAFFID)
      references STAFF (STAFFID);

alter table TEACHING_INFORMATION
   add constraint FK_TEACHING_RELATIONS_COURSE foreign key (COURSEID)
      references COURSE (COURSEID);

alter table TUT_PRAC
   add constraint FK_TUT_PRAC_HAS_COURSE foreign key (COURSEID)
      references COURSE (COURSEID);

alter table TUT_PRAC
   add constraint FK_TUT_PRAC_RELATIONS_STAFF foreign key (STAFFID)
      references STAFF (STAFFID);

Answer 1

SET SERVEROUTPUT ON
DECLARE
CID char(8):='isys228';
CNAME varchar2(20):='Greendata';
PID char(8):='isys114';
DID char(8):='comp3647';
BEGIN
DBMS_OUTPUT.PUT_LINE('The course has been enrolled');
END;

尝试改为

Answer 2

你得到了什么错误信息？

尝试使用此代码。

SET SERVEROUTPUT ON
DECLARE
CID COURSE.COURSEID%TYPE:='isys228';
CNAME COURSE.COURSENAME%TYPE:='Greendata';
PID HAS_PREREQUISITE.PREREQUISITEID%TYPE:='isys114';
DID DEPARTMENT.DEPTID%TYPE:='comp3647';
BEGIN
DBMS_OUTPUT.PUT_LINE('The course has been enrolled');
NEW_COURSE(CNAME,CID,PID,DID);
END;
/

Answer 3

您需要提交插入内容。试试

commit;

之后

NEW_COURSE(CNAME,CID,PID,DID);

或者如果您想要提交过程

INSERT INTO DEPARTMENT VALUES (DID,NULL,NULL,NULL);        /* edit the statement to fit the table structure. also 'NULL' or null ? */
COMMIT;

EDIT 重新排序您的插入订单，因为COURSE有一个FK到DEPARTMENT

-- FIRST THE INSERT IN DEPARTMENT
INSERT INTO DEPARTMENT VALUES (DID,NULL,NULL,NULL);        /* edit the statement to fit the table structure. also 'NULL' or null ? */

 INSERT INTO COURSE VALUES(CID,CNAME,DID,NULL,NULL,NULL,NULL,NULL,NULL);  /*     edit the statement to fit the table structure  also 'NULL' or null ?*/

 INSERT INTO HAS_PREREQUISITE VALUES(CID,PID);         /* the table only has 2 colums */

NEW_COURSE pl / sql程序引发了异常，我无法弄明白

3 个答案: