Question

我遇到这两个错误：

错误：没有唯一约束匹配引用表“flight”的给定键

*** 错误 ** *

错误：没有唯一约束匹配引用表“flight”的给定键

这是我的代码：

CREATE TABLE Staff (
 EmployeeNumber int NOT NULL,
 FirstName char(15) NOT NULL,
 LastName char(15) NOT NULL,
 SocialSecurity int NOT NULL,
 Sex  char(1) NOT NULL,
 Address  char(20) NOT NULL,
 City  char(20) NOT NULL,
 Province char(15) NOT NULL,
 Country  char(20) NOT NULL,
 Primary Key (EmployeeNumber)
 );

CREATE TABLE FlightAttendent (
 FALN  int,
 StaffRole char (20) NOT NULL,
 EmployeeNumber int NOT NULL,
 Foreign Key (EmployeeNumber) References Staff(EmployeeNumber),
 Primary Key (FALN)
 );

Create TABLE AircraftType (
 ACType  char (10),
 Instrument char(1) NOT NULL,
 Engines  int NOT NULL,
 CrewCount int NOT NULL,
 PassengerCount int NOT NULL,
 Primary Key (ACType)
 );


CREATE TABLE Pilot (
 PILN  int,
 MedicalValid date NOT NULL,
 StaffRole char (20) NOT NULL,
 EmployeeNumber  int NOT NULL,
 AircraftType char (10) NOT NULL,
 Foreign Key (EmployeeNumber) references Staff(EmployeeNumber),
 Foreign Key (AircraftType) References AircraftType(ACType),
 Primary Key (PILN)
 );

Create TABLE Aircraft (
 AircraftID  char(6) NOT NULL,
 AircraftManufacturer char(10) NOT NULL,
 AircraftType  char(10) NOT NULL,
 Foreign Key (AircraftType) References AircraftType(ACType),
 Primary Key (AircraftID)
 );

CREATE Table Airport (
 AirportCode char(4) NOT NULL,
 AirportName char(40) NOT NULL,
 City  char(20) NOT NULL,
 Country  char(20) NOT NULL,
 Continent char(20) NOT NULL,
 Primary Key (AirportCode)
 );

Create TABLE Flight (
 FlightID  char (20),
 FlightDate  date,
 AircraftID  char(6) NOT NULL,
 ArrivalAirport  char(4) NOT NULL,
 DepartureAirport char(4) NOT NULL,
 PRIMARY KEY (FlightID, FlightDate),
 FOREIGN Key (ArrivalAirport) references Airport(AirportCode),
 FOREIGN Key (DepartureAirport) references Airport(AirportCode),
 FOREIGN KEY (AircraftID) references Aircraft(AircraftID)
 );


Create TABLE FlightCrew (
 FlightID char (20) REFERENCES Flight(FlightID) ON DELETE CASCADE,
 FlightDate date REFERENCES Flight(FlightDate) ON DELETE CASCADE,
 EmployeeNumber int NOT NULL,
 StaffRole char(20) NOT NULL,
 PRIMARY KEY(FlightID, FlightDate),
 Foreign Key (EmployeeNumber) references Staff(EmployeeNumber)
 );

CREATE Table Passenger (
 PassengerNumber int,
 PassportNumber int NOT NULL,
 Citizenship char (20) NOT NULL,
 FirstName char (20) NOT NULL,
 LastName char (20) NOT NULL,
 Primary Key (PassengerNumber)
 );

CREATE Table PassengerManifest (
 FlightID char(20),
 FlightDate date,
 PassengerNumber int NOT NULL,
 Foreign Key (FlightDate) References Flight(FlightDate),
 Foreign Key (PassengerNumber) References Passenger(PassengerNumber),
 Primary Key (FlightID, FlightDate)
 );

我做错了什么？谢谢！

Answer 1

如果主键中有多个值，则需要以不同的方式引用它作为外键。

基本上，当你说

时

FlightID char (20) REFERENCES Flight(FlightID) ON DELETE CASCADE,

PostgreSQL检查该主键是否存在（因为该表上的主键是（fligtid，flightdate））。

因此，在引用航班表时删除REFERENCES子句，然后添加

FOREIGN KEY (FlightID, FlightDate) REFERENCES Flight (FlightID, FlightDate)

以您在某些其他表定义中的方式。

PostgreSQL约束问题

1 个答案: