獲取1215錯誤'無法添加外鍵約束

Question

任何人都可以從我的代碼中看到爲什麼我得到這個錯誤？這對我來說是新的，所以仍然在學習。由於

CREATE TABLE DIRECTOR(
DIRECTOR_ID VARCHAR (6) PRIMARY KEY NOT NULL, 
F_NAME VARCHAR (10) NOT NULL, 
L_NAME VARCHAR (10) NOT NULL); 

CREATE TABLE TITLE_DIRECTOR(
TITLE_ID VARCHAR (10) NOT NULL, 
DIRECTOR_ID VARCHAR (6) NOT NULL, 
TITLE_NAME VARCHAR (50) NOT NULL, 
DIRECTOR_FNAME VARCHAR (10) NOT NULL, 
DIRECTOR_LNAME VARCHAR (10) NOT NULL, 
INDEX (DIRECTOR_ID), 
FOREIGN KEY (DIRECTOR_ID) REFERENCES DIRECTOR (DIRECTOR_ID)); 

Answer 1

也許你的MyISAM作爲默認引擎，只是把隱性引擎InnoDB的：

CREATE TABLE DIRECTOR(
    DIRECTOR_ID VARCHAR (6) PRIMARY KEY NOT NULL, 
    F_NAME VARCHAR (10) NOT NULL, 
    L_NAME VARCHAR (10) NOT NULL 
) ENGINE = InnoDB; 



CREATE TABLE TITLE_DIRECTOR(
    TITLE_ID VARCHAR (10) NOT NULL, 
    DIRECTOR_ID VARCHAR (6) NOT NULL, 
    TITLE_NAME VARCHAR (50) NOT NULL, 
    DIRECTOR_FNAME VARCHAR (10) NOT NULL, 
    DIRECTOR_LNAME VARCHAR (10) NOT NULL, 
    INDEX (DIRECTOR_ID), 
    FOREIGN KEY (DIRECTOR_ID) REFERENCES DIRECTOR (DIRECTOR_ID) 
)ENGINE = InnoDB;;