外键出乎意料

Question

我正在使用MySQL工作台，我正在尝试使用SQL Query创建一个包含外键的表。我对外国部分有问题。

create table employee_position
(
ePID int primary key,
ePName varchar(45) not null,
eID int foreign key references employee_profile(eID)
)

Answer 1

你的语法错了。尝试：

create table employee_position
(
ePID int primary key,
ePName varchar(45) not null,
eID int,
foreign key (keyname) references employee_profile(eID)
)

有关详细信息，请参阅mysql documentation

Answer 2

create table employee_position
(
  ePID int primary key,
  ePName varchar(45) not null,
  eID int,
  foreign key (eID) references employee_profile(eID)
)

SQLFiddle demo

Answer 3

检查MySQL中的FOREIGN KEYS。

试试这个：

CREATE TABLE employee_position
(
   ePID INT NOT NULL AUTO_INCREMENT,
   ePName VARCHAR(45) NOT NULL,
   eID INT NOT NULL,
   PRIMARY KEY (ePID),
   KEY CustomerID (eID),
   CONSTRAINT FK_employee_position_EP 
           FOREIGN KEY (eID) 
           REFERENCES employee_profile (eID) ON DELETE CASCADE ON UPDATE CASCADE
);