CODEWITHSUNDEEP
sqlpostgresql
user1438005
user1438005

Reputation: 21

PostgreSQL constraint problems

I am having these two errors :

ERROR: there is no unique constraint matching given keys for referenced table "flight"

*** Error ***

ERROR: there is no unique constraint matching given keys for referenced table "flight"

This is my code :

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)
 );

What did I do wrong? Thanks!

Upvotes: 1

Views: 5603

Answers (1)

jmelesky
jmelesky

Reputation: 749

When you have multiple values in a primary key, you need to reference it differently as a foreign key.

Basically, when you say

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

PostgreSQL checks for that primary key, which doesn't exist (since the primary key on that table is (flightid, flightdate)).

So drop the REFERENCES clauses when referencing the flight table, and add

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

In the manner you have in some of the other table definitions.

Upvotes: 5

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