Question

mysql 添加外键报错，Error Code: 1215. Cannot add foreign key constraint

我的四个表如下：

create table TUser(
uid int auto_increment primary key,
employNo varchar(20) not null unique,
employName varchar(20) not null,
password varchar(20) not null,
administratorflag varchar(5) not null,
mobile varchar(20),
email varchar(64),
gen_time datetime not null,
login_time datetime,
last_login_time datetime,
count int not null
)

create table TDepartment(
did int primary key auto_increment,
deptNo varchar(20) not null unique,
deptName varchar(64) not null,
pdid int ,
cid int not null,
memo varchar(200),
foreign key(cid) references TCompany(cid) on delete cascade on update cascade
)

-- 职位表（TPosition）
create table TPostition(
pid int primary key auto_increment,
positionCode varchar(20) not null unique,
positionName varchar(64) not null
)

但是在创建下面这个表的时候报错。
create table TDepartmentUserRelation(
duid int not null auto_increment,
uid int not null,
did int not null,
pid int not null,
memo varchar(200),
primary key(duid),
foreign key(uid) references TUser(uid) on delete cascade on update cascade,
foreign key(did) references TDepartment(did) on delete cascade on update cascade,
foreign key(pid) references TPosition(pid) on delete cascade on update cascade
)
报的是
Error Code: 1215. Cannot add foreign key constraint
。。先谢谢了！

Answer 1

mysql中，两个表要建外键必须都是InnoDB表，MyISAM表暂时不支持外键，估计就是引擎的问题

Answer 2

create table TPostition(
pid int primary key auto_increment,
positionCode varchar(20) not null unique,
positionName varchar(64) not null
)
与
foreign key(pid) references TPosition(pid) on delete cascade on update cascade
)
中的TPostition拼错了！！