Mysql Workbench錯誤1215：無法將外鍵添加到約束

Question

所以我試圖向表中添加一個外鍵，但不斷出現此錯誤：

錯誤代碼：1215。無法添加外鍵約束

代碼如下

create table Students

(
    ID char(10) primary key not null,
    StudentsName varchar(30),
    Address varchar(40),
    StudentsTelephone varchar(20),
    constraint M1 check(len(NIM)=10),
    constraint M2 check(NIM like '[0-9][0-9][0-9][0-9][0-9][0-9][0-9][0-9][0-9][0-9]')
)

create table Lecturers

(
    CodeLecturer char(5) primary key not null,
    LecturersName varchar(30),
    Salary numeric,
    Address varchar(40),
    LecturerTelephone varchar(20),
    constraint D1 check(len(CodeLecturer)=5),
    constraint D2 check(CodeLecturer like 'D[0-9][0-9][0-9][0-9]')

)

這是外鍵代碼

create table TrHeaderKampus

(
    TransactionCOde char(5) primary key not null,
    ID char(10) not null,
    CodeLecturer char(5) not null,
    DateandTime datetime,
    constraint H1 check(len(TransactioniCode)=5),
    constraint H2 check(TransactionCode like 'TR[0-9][0-9][0-9]'),
    foreign key(ID)REFERENCES Students ON UPDATE CASCADE ON DELETE CASCADE,
    foreign key(CodeLecturer)REFERENCES Lecturers ON UPDATE CASCADE ON DELETE CASCADE
)

Answer 1

正如MySQL有關使用外鍵的文檔所述：您不僅需要提供表，還需要提供外鍵引用的字段。

 [CONSTRAINT [symbol]] FOREIGN KEY [index_name] (index_col_name, ...) REFERENCES tbl_name (index_col_name,...) [ON DELETE reference_option] [ON UPDATE reference_option] 

將字段名稱添加到它們引用的外鍵約束中。