# More JOIN operations

### Movie Database

This tutorial introduces the notion of a join. The database consists of three tables movie , actor and casting .

movie(id, title, yr, director)
actor(id, name)
casting(movieid, actorid, ord)

## Let's go to work.

Limbering up

List the films where the yr is 1962 [Show id, title]

movie(id,title,yr,director)
SELECT id, title
FROM movie
WHERE yr=1962
SELECT id, title
FROM movie
WHERE yr=1962

Give year of 'Citizen Kane'.

movie(id,title,yr,director)

SELECT yr
FROM movie
WHERE title='Citizen Kane'

List all of the Star Trek movies, include the id title and yr. (All of these movies include the words Star Trek in the title.)

movie(id,title,yr,director)

SELECT id,title, yr FROM movie
WHERE title LIKE 'Star Trek%'
ORDER BY yr

## Looking at the id field.

What are the titles of the films with id 11768, 11955, 21191

movie(id,title,yr,director)

SELECT title
FROM movie
WHERE id IN (11768, 11955, 21191)

What id number does the actor 'Glenn Close' have?

movie(id,title,yr,director)
actor(id,name)
casting(movieid,actorid,ord)

SELECT id FROM actor
WHERE name= 'Glenn Close'

What is the id of the film 'Casablanca'

movie(id,title,yr,director)

SELECT id
FROM movie
WHERE title='Casablanca'

## Get to the point

Obtain the cast list for 'Casablanca'. Use the id value that you obtained in the previous question.

actor(id,name)
casting(movieid,actorid,ord)

SELECT name
FROM casting, actor
WHERE movieid=(SELECT id
FROM movie
WHERE title='Casablanca')
AND actorid=actor.id

Obtain the cast list for the film 'Alien'

movie(id,title,yr,director)
actor(id,name)
casting(movieid,actorid,ord)

SELECT name
FROM movie, casting, actor
WHERE title='Alien'
AND movieid=movie.id
AND actorid=actor.id

List the films in which 'Harrison Ford' has appeared

movie(id,title,yr,director)
actor(id,name)
casting(movieid,actorid,ord)

SELECT title
FROM movie, casting, actor
WHERE name='Harrison Ford'
AND movieid=movie.id
AND actorid=actor.id

List the films where 'Harrison Ford' has appeared - but not in the star role. [Note: the ord field of casting gives the position of the actor. If ord=1 then this actor is in the starring role]

movie(id,title,yr,director)
actor(id,name)
casting(movieid,actorid,ord)

SELECT title
FROM movie, casting, actor
WHERE name='Harrison Ford'
AND movieid=movie.id
AND actorid=actor.id
AND ord<>1

List the films together with the leading star for all 1962 films.

movie(id,title,yr,director)
actor(id,name)
casting(movieid,actorid,ord)

SELECT title, name
FROM movie, casting, actor
WHERE yr=1962
AND movieid=movie.id
AND actorid=actor.id
AND ord=1

## That's plenty joins for now. Students with an unhealthy interest in databases or movies may try the following harder questions; although they might be better advised to go out and get some fresh air.

List the films together with the leading star for all 1962 films.

movie(id,title,yr,director)
actor(id,name)
casting(movieid,actorid,ord)

SELECT yr,COUNT(title) FROM
movie JOIN casting ON movie.id=movieid
JOIN actor   ON actorid=actor.id
WHERE name='John Travolta'
GROUP BY yr
HAVING COUNT(title)=(SELECT MAX(c) FROM
(SELECT yr,COUNT(title) AS c FROM
movie JOIN casting ON movie.id=movieid
JOIN actor   ON actorid=actor.id
WHERE name='John Travolta'
GROUP BY yr) AS t
)

List the film title and the leading actor for all of 'Julie Andrews' films.

movie(id,title,yr,director)
actor(id,name)
casting(movieid,actorid,ord)

SELECT title, name
FROM movie, casting, actor
WHERE movieid=movie.id
AND actorid=actor.id
AND ord=1
AND movieid IN
(SELECT movieid FROM casting, actor
WHERE actorid=actor.id
AND name='Julie Andrews')

Obtain a list of actors in who have had at least 30 starring roles.

movie(id,title,yr,director)
actor(id,name)
casting(movieid,actorid,ord)

SELECT name
FROM casting JOIN actor
ON  actorid = actor.id
WHERE ord=1
GROUP BY name
HAVING COUNT(movieid)>=30

List the 1978 films by order of cast list size.

movie(id,title,yr,director)
actor(id,name)
casting(movieid,actorid,ord)

SELECT title, COUNT(actorid)
FROM casting, movie
WHERE yr=1978
AND movieid=movie.id
GROUP BY title
ORDER BY 2 DESC

List all the people who have worked with 'Art Garfunkel'.

movie(id,title,yr,director)
actor(id,name)
casting(movieid,actorid,ord)

SELECT DISTINCT d.name
FROM actor d JOIN casting a ON (a.actorid=d.id)
JOIN casting b ON (a.movieid=b.movieid)
JOIN actor c ON (b.actorid=c.id
AND c.name='Art Garfunkel')
WHERE d.id!=c.id