table 中不存在键列。 SQL

Question

所以我尝试查找其他问题并进行了尝试，但我无法弄清楚为什么我的 SQL 不起作用。它一直说 DepartmentID table 不存在，我已将其声明为 Department.

下的主键

CREATE TABLE EMPLOYEE(
SSN INT NOT NULL,
WorkID INT NOT NULL,
BirthDate DATE NOT NULL,
Name VARCHAR(20) NOT NULL,
UNIQUE(WorkID),
PRIMARY KEY(SSN),
FOREIGN KEY(DepartmentID) REFERENCES DEPARTMENT(DepartmentID),
FOREIGN KEY(DeviceID) REFERENCES DEVICE(DeviceID)
);

CREATE TABLE DEPARTMENT(
DepartmentID INT NOT NULL,
DepartmentName VARCHAR (20) NOT NULL,
PRIMARY KEY(DepartmentID),
UNIQUE(DepartmentName)
);

CREATE TABLE PRODUCT(
ProductID INT NOT NULL,
Name VARCHAR(20) NOT NULL,
Isle VARCHAR(5) NOT NULL,
Company VARCHAR(20) NOT NULL,
PRIMARY KEY(ProductID),
FOREIGN KEY(DepartmentID) REFERENCES DEPARTMENT(DepartmentID)
);


CREATE TABLE DEVICE(
DeviceID INT NOT NULL,
DateReceived DATE NOT NULL,
PRIMARY KEY(DeviceID)
);

CREATE TABLE SALES(
SalesID INT NOT NULL,
Profit INT NOT NULL,
Revenue INT NOT NULL,
PRIMARY KEY(SalesID)
);

CREATE TABLE AmountSold(
FOREIGN KEY (SalesID) REFERENCES SALES(SalesID),
FOREIGN KEY (ProductID) REFERENCES PRODUCT(ProductID)
);

Answer 1

这里的问题是您没有在 Employee table 中声明 DepartmentId 列。还首先执行父 table，然后执行引用

的父 table

 CREATE TABLE DEPARTMENT(
 DepartmentID INT NOT NULL,
 DepartmentName VARCHAR (20) NOT NULL,
 PRIMARY KEY(DepartmentID)
 );

 CREATE TABLE DEVICE(
 DeviceID INT NOT NULL,
 DateReceived DATE NOT NULL,
 PRIMARY KEY(DeviceID)
 );

 CREATE TABLE EMPLOYEE(
 SSN INT NOT NULL,
 WorkID INT NOT NULL,
 BirthDate DATE NOT NULL,
 Name VARCHAR(20) NOT NULL,
 DepartmentID INT,
 DeviceID INT ,
 UNIQUE(WorkID),
 PRIMARY KEY(SSN),
 FOREIGN KEY(DepartmentID) REFERENCES DEPARTMENT(DepartmentID),
 FOREIGN KEY(DeviceID) REFERENCES DEVICE(DeviceID)
 );

 CREATE TABLE PRODUCT(
 ProductID INT NOT NULL,
 Name VARCHAR(20) NOT NULL,
 Isle VARCHAR(5) NOT NULL,
 Company VARCHAR(20) NOT NULL,
 DepartmentID INT,
 PRIMARY KEY(ProductID),
 FOREIGN KEY(DepartmentID) REFERENCES DEPARTMENT(DepartmentID)
 );

 CREATE TABLE SALES(
 SalesID INT NOT NULL,
 Profit INT NOT NULL,
 Revenue INT NOT NULL,
 PRIMARY KEY(SalesID)
 );

 CREATE TABLE AmountSold(
 SalesId INT NOT NULL,
 ProductId INT NOT NULL,
 FOREIGN KEY (SalesID) REFERENCES SALES(SalesID),
 FOREIGN KEY (ProductID) REFERENCES PRODUCT(ProductID)
 );

Answer 2

问题是您创建的是外键，但 DepartmentID 列在您引用的那个 table 上不存在，第二个是你的订单不正确。

CREATE TABLE DEPARTMENT(
DepartmentID INT NOT NULL,
DepartmentName VARCHAR (20) NOT NULL,
PRIMARY KEY(DepartmentID),
UNIQUE(DepartmentName)
);

CREATE TABLE DEVICE(
DeviceID INT NOT NULL,
DateReceived DATE NOT NULL,
PRIMARY KEY(DeviceID)
);

CREATE TABLE EMPLOYEE(
SSN INT NOT NULL,
WorkID INT NOT NULL,
BirthDate DATE NOT NULL,
DepartmentID INT NOT NULL,
DeviceID INT NOT NULL,
Name VARCHAR(20) NOT NULL,
UNIQUE(WorkID),
PRIMARY KEY(SSN),
FOREIGN KEY(DepartmentID) REFERENCES DEPARTMENT(DepartmentID),
FOREIGN KEY(DeviceID) REFERENCES DEVICE(DeviceID)
);



CREATE TABLE PRODUCT(
ProductID INT NOT NULL,
Name VARCHAR(20) NOT NULL,
DepartmentID INT NOT NULL,
Isle VARCHAR(5) NOT NULL,
Company VARCHAR(20) NOT NULL,
PRIMARY KEY(ProductID),
FOREIGN KEY(DepartmentID) REFERENCES DEPARTMENT(DepartmentID)
);




CREATE TABLE SALES(
SalesID INT NOT NULL,
Profit INT NOT NULL,
Revenue INT NOT NULL,
PRIMARY KEY(SalesID)
);

CREATE TABLE AmountSold(
FOREIGN KEY (SalesID) REFERENCES SALES(SalesID),
FOREIGN KEY (ProductID) REFERENCES PRODUCT(ProductID)
);

table 中不存在键列。 SQL

Key column does not exist in table. SQL

sql

ddl