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)

More details about the database.

movie

Field name	Type	Notes
id	INTEGER	An arbitrary unique identifier
title	CHAR(70)	The name of the film - usually in the language of the first release.
yr	DECIMAL(4)	Year of first release.
director	INT	A reference to the actor table.
budget	INTEGER	How much the movie cost to make (in a variety of currencies unfortunately).
gross	INTEGER	How much the movie made at the box office.

actor

Field name	Type	Notes
id	INTEGER	An arbitrary unique identifier
name	CHAR(36)	The name of the actor (the term actor is used to refer to both male and female thesps.)

casting

Field name	Type	Notes
movieid	INTEGER	A reference to the movie table.
actorid	INTEGER	A reference to the actor table.
ord	INTEGER	The ordinal position of the actor in the cast list. The star of the movie will have ord value 1 the co-star will have value 2, ...

Summary

Let's go to work.

Limbering up

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

SELECT id, title
 FROM movie
 WHERE yr=1962

SELECT id, title
 FROM movie
 WHERE yr=1962

Give year of 'Citizen Kane'.

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.)

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

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

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

SELECT id FROM actor
  WHERE name= 'Glenn Close'

What is the id of the film 'Casablanca'

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.

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'

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

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]

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.

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

Harder Questions

Which were the busiest years for 'John Travolta'. Show the number of movies he made for each year.

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
)

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.

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.

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.

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'.

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

Clear you results

JOIN Quiz 2

That is definitely enough. Students should, under no circumstances look at the next tutorial, concerning outer joins.