Violation of PRIMARY KEY constraint PK_Casting - sql

Question

I'm trying to add a new data base through a script, but getting some errors, already tried to let out the double fields, but that didn't work for me.
USE master
GO
IF EXISTS (SELECT * FROM sysdatabases WHERE NAME = 'MijnFilms')
BEGIN
ALTER DATABASE MijnFilms SET SINGLE_USER WITH ROLLBACK IMMEDIATE
DROP DATABASE MijnFilms
END
GO
-- Creatie databank Bibliotheek
CREATE DATABASE MijnFilms
GO
USE MijnFilms
GO
--Creatie tabel AUTEUR
CREATE TABLE ACTEUR
(
Acteur_id int NOT NULL,
ActeurNaam nvarchar(40),
CONSTRAINT PK_Acteur PRIMARY KEY(acteur_id)
)
GO
--Creatie tabel CATEGORIE
CREATE TABLE CASTING
(
Film_id int NOT NULL,
Acteur_id int NOT NULL,
CONSTRAINT PK_Casting PRIMARY KEY(Film_id),
CONSTRAINT FK1_Casting FOREIGN KEY(Acteur_id) REFERENCES Acteur(acteur_id)
)
GO
--Creatie tabel BOEKEN
CREATE TABLE FILM
(
Film_id int NOT NULL,
Titel nvarchar(40),
Jaar smallint,
Score int,
Stemmen int,
CONSTRAINT FK1_Film FOREIGN KEY(Film_id) REFERENCES Casting(film_id),
)
GO
--Opvullen van de tabellen met testdata
INSERT INTO ACTEUR(Acteur_id, ActeurNaam) VALUES (1, 'Tom Hanks')
INSERT INTO ACTEUR(Acteur_id, ActeurNaam) VALUES (2, 'Helen Hunt')
INSERT INTO ACTEUR(Acteur_id, ActeurNaam) VALUES (3, 'Catherine Zeta Jones')
GO
INSERT INTO CASTING (Film_id, Acteur_id) VALUES (1, 1)
INSERT INTO CASTING (Film_id, Acteur_id) VALUES (1, 2)
INSERT INTO CASTING (Film_id, Acteur_id) VALUES (2, 1)
INSERT INTO CASTING (Film_id, Acteur_id) VALUES (2, 3)
GO
INSERT INTO FILM(Film_id, Titel, jaar, Score, Stemmen) VALUES (1, 'Cast Away', 2000, 75,1)
INSERT INTO FILM(Film_id, Titel, jaar, Score, Stemmen) VALUES (2, 'The Terminal', 2004, 62,1)
GO
Right now, I get an error:
Msg 2627, Level 14, State 1, Line 60
Violation of PRIMARY KEY constraint 'PK_Casting'. Cannot insert duplicate key in object 'dbo.CASTING'. The duplicate key value is (2).

Answer 1

Well, you're trying to insert a film_id of 1 (and 2) into casting twice but primary keys need to be unique.
You could use a composite primary key here, consisting of the film's and the actor's ID.
Also the film's ID should be the primary key in film and a foreign key in casting not the other way round. That requires film to be created before casting though. That also applies for the INSERTs -- film has to come before casting.
...
CREATE TABLE film
(film_id integer
NOT NULL,
titel nvarchar(40),
jaar smallint,
score integer,
stemmen integer,
CONSTRAINT pk_film
PRIMARY KEY (film_id));
CREATE TABLE acteur
(acteur_id integer
NOT NULL,
acteurnaam nvarchar(40),
CONSTRAINT pk_acteur
PRIMARY KEY (acteur_id));
CREATE TABLE casting
(film_id integer
NOT NULL,
acteur_id integer
NOT NULL,
CONSTRAINT pk_casting
PRIMARY KEY (film_id,
acteur_id),
CONSTRAINT fk1_casting
FOREIGN KEY (film_id)
REFERENCES film
(film_id),
CONSTRAINT fk2_casting
FOREIGN KEY (acteur_id)
REFERENCES acteur
(acteur_id));
...
INSERT INTO film ...
INSERT INTO acteur ...
INSERT INTO casting ...

Answer 2

You are creating the table with constraints
CREATE TABLE CASTING
(
Film_id int NOT NULL,
Acteur_id int NOT NULL,
CONSTRAINT PK_Casting PRIMARY KEY(Film_id),
CONSTRAINT FK1_Casting FOREIGN KEY(Acteur_id) REFERENCES Acteur(acteur_id)
)
GO
and then you are inserting duplicated records in the table
INSERT INTO CASTING (Film_id, Acteur_id) VALUES (1, 1)
INSERT INTO CASTING (Film_id, Acteur_id) VALUES (1, 2)
INSERT INTO CASTING (Film_id, Acteur_id) VALUES (2, 1)
INSERT INTO CASTING (Film_id, Acteur_id) VALUES (2, 3)
You need to remove the constraint or you need to make COMPOSITE KEY by creating the key on FILM_ID and ACTEUR_ID