获取1215错误'无法添加外键约束

Question

任何人都可以从我的代码中看到为什么我得到这个错误？这对我来说是新的，所以仍然在学习。由于

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

也许你的MyISAM作为默认引擎，只是把隐性引擎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;;