Question

我不知道为什么它不会让我创建表注册。我只需要参考学生，uniadmin和课程，我已经在注册之前创建了它们。

它们的名称，属性类型和长度都相同，所以我不知道这里有什么不对。它发生在我使用外键引用的所有表中......所以它必须与它们有关，我会假设。

我收到错误： SQL查询：

CREATE TABLE Enrolment(

EnrolmentIDCHAR( 3 ) NOT NULL ,
StudentIDCHAR( 3 ) NOT NULL ,
StaffIDCHAR( 3 ) NOT NULL ,
CourseIDCHAR( 7 ) NOT NULL ,
CampusCHAR( 2 ) NOT NULL ,
Trimester TINYINT( 1 ) NOT NULL ,
CONSTRAINT PK_Enrolment PRIMARY KEY ( EnrolmentID ) ,
CONSTRAINT FK1_Enrolment FOREIGN KEY ( StudentID ) REFERENCES Student( StudentID ) ,
CONSTRAINT FK2_Enrolment FOREIGN KEY ( StaffID ) REFERENCES UniversityAdmin( StaffID ) ,
CONSTRAINT FK3_Enrolment FOREIGN KEY ( CourseID ) REFERENCES Course( CourseID ) ,
CONSTRAINT FK4_Enrolment FOREIGN KEY ( Campus ) REFERENCES Course( Campus ) ,
CONSTRAINT FK5_Enrolment FOREIGN KEY ( Trimester ) REFERENCES Course( Trimester ) /*constraint Check_EnrolmentCampus check (Campus in ('GC', 'BR')*/
);

MySQL said: Documentation

#1005 - Can't create table 'university.Enrolment' (errno: 150) (Details…)

＆＃34;详情＆＃34;说：

InnoDB文档

支持事务，行级锁定和外键

[变量|缓冲池| InnoDB状态]

我的代码：

DROP DATABASE IF EXISTS university;
CREATE DATABASE IF NOT EXISTS university;
USE university;

drop table if exists Student;
drop table if exists UniversityAdmin;
drop table if exists Course;
drop table if exists Academic;
drop table if exists Teaches;
drop table if exists Administers;
drop table if exists Manages;
drop table if exists Enrolment;
drop table if exists Scored;

Create table Student(
            StudentID Char(3) not null,
            Password Varchar(20) not null,
            FirstName Varchar(15) not null,
            MiddleName Varchar(15),
            LastName Varchar(15) not null,
            DateOfBirth Date not null,
            Sex Char(1) not null,
            HomeAddress Varchar(60) not null,
            PhoneNumber Varchar(10) not null,
            constraint PK_Student primary key(StudentID)
            /*constraint Check_StudentSex check (Sex in ('M', 'F')*/
            );

Create table UniversityAdmin(
            StaffID Char(3) not null,
            Password Varchar(20) not null,
            Duty Varchar(20) not null,
            FirstName Varchar(15) not null,
            MiddleName Varchar(15),
            LastName Varchar(15) not null,
            DateOfBirth Date not null,
            Sex Char(1) not null,
            HomeAddress Varchar(60) not null,
            PhoneNumber Varchar(10) not null,
            constraint PK_UniversityAdmin primary key(StaffID)
            /*constraint Check_UniversityAdminSex check (Sex in ('M', 'F')*/
            );

Create table Course(
            CourseID Char(7) not null,
            Campus Char(2) not null,
            Trimester TinyInt(1) not null,
            CourseName Varchar(50) not null,
            Convenor Varchar(30) not null,
            Prerequisite Char(7),
            Year TinyInt(4) not null,
            constraint PK_Course primary key(CourseID, Campus, Trimester)
            /*constraint Check_CourseCampus check (Campus in ('GC', 'BR')*/
            );

Create table Academic(
            StaffID Char(3) not null,
            Password Varchar(20) not null,
            Position Varchar(30) not null,
            FirstName Varchar(15) not null,
            MiddleName Varchar(15),
            LastName Varchar(15) not null,
            DateOfBirth Date not null,
            Sex Char(1) not null,
            HomeAddress Varchar(60) not null,
            PhoneNumber Varchar(10) not null,
            constraint PK_Academic primary key(StaffID)
            /*constraint Check_AcademicSex check (Sex in ('M', 'F')*/
            );      

Create table Enrolment(
            EnrolmentID Char(3) not null,
            StudentID Char(3) not null,
            StaffID Char(3) not null,
            CourseID Char(7) not null,
            Campus Char(2) not null,
            Trimester TinyInt(1) not null,
            constraint PK_Enrolment primary key (EnrolmentID),
            constraint FK1_Enrolment foreign key (StudentID) references Student(StudentID),
            constraint FK2_Enrolment foreign key (StaffID) references UniversityAdmin(StaffID),
            constraint FK3_Enrolment foreign key (CourseID) references Course(CourseID),
            constraint FK4_Enrolment foreign key (Campus) references Course(Campus),
            constraint FK5_Enrolment foreign key (Trimester) references Course(Trimester)
            /*constraint Check_EnrolmentCampus check (Campus in ('GC', 'BR')*/
            );

Answer 1

如果您已经创建了其他表，则可以像这样更改Course表：

ALTER TABLE Course
      ADD INDEX(Campus),
      ADD INDEX(Trimester);

像这样，您可以在Enrolment表中使用这两列，例如外键，否则在创建此表时会出错。

如果要删除表Course，则必须先添加外键后删除Enrolment。

MySQL - ＃1005 - 无法创建table＆＃39; university.Enrolment＆＃39; （错误号码：150）（详情......）

1 个答案: