SQL exercises on movie Database: Find the titles of all movies that have no ratings

SQL movie Database: Subquery Exercise-7 with Solution

7. From the following table, write a SQL query to search for movies that do not have any ratings. Return movie title.

 mov_id |                     mov_title                      | mov_year | mov_time |    mov_lang     | mov_dt_rel | mov_rel_country
--------+----------------------------------------------------+----------+----------+-----------------+------------+-----------------
    901 | Vertigo                                            |     1958 |      128 | English         | 1958-08-24 | UK
    902 | The Innocents                                      |     1961 |      100 | English         | 1962-02-19 | SW
    903 | Lawrence of Arabia                                 |     1962 |      216 | English         | 1962-12-11 | UK
    904 | The Deer Hunter                                    |     1978 |      183 | English         | 1979-03-08 | UK
    905 | Amadeus                                            |     1984 |      160 | English         | 1985-01-07 | UK
    906 | Blade Runner                                       |     1982 |      117 | English         | 1982-09-09 | UK
    907 | Eyes Wide Shut                                     |     1999 |      159 | English         |            | UK
    908 | The Usual Suspects                                 |     1995 |      106 | English         | 1995-08-25 | UK
    909 | Chinatown                                          |     1974 |      130 | English         | 1974-08-09 | UK
    910 | Boogie Nights                                      |     1997 |      155 | English         | 1998-02-16 | UK
    911 | Annie Hall                                         |     1977 |       93 | English         | 1977-04-20 | USA
    912 | Princess Mononoke                                  |     1997 |      134 | Japanese        | 2001-10-19 | UK
    913 | The Shawshank Redemption                           |     1994 |      142 | English         | 1995-02-17 | UK
    914 | American Beauty                                    |     1999 |      122 | English         |            | UK
    915 | Titanic                                            |     1997 |      194 | English         | 1998-01-23 | UK
    916 | Good Will Hunting                                  |     1997 |      126 | English         | 1998-06-03 | UK
    917 | Deliverance                                        |     1972 |      109 | English         | 1982-10-05 | UK
    918 | Trainspotting                                      |     1996 |       94 | English         | 1996-02-23 | UK
    919 | The Prestige                                       |     2006 |      130 | English         | 2006-11-10 | UK
    920 | Donnie Darko                                       |     2001 |      113 | English         |            | UK
    921 | Slumdog Millionaire                                |     2008 |      120 | English         | 2009-01-09 | UK
    922 | Aliens                                             |     1986 |      137 | English         | 1986-08-29 | UK
    923 | Beyond the Sea                                     |     2004 |      118 | English         | 2004-11-26 | UK
    924 | Avatar                                             |     2009 |      162 | English         | 2009-12-17 | UK
    926 | Seven Samurai                                      |     1954 |      207 | Japanese        | 1954-04-26 | JP
    927 | Spirited Away                                      |     2001 |      125 | Japanese        | 2003-09-12 | UK
    928 | Back to the Future                                 |     1985 |      116 | English         | 1985-12-04 | UK
    925 | Braveheart                                         |     1995 |      178 | English         | 1995-09-08 | UK

 mov_id | rev_id | rev_stars | num_o_ratings
--------+--------+-----------+---------------
    901 |   9001 |      8.40 |        263575
    902 |   9002 |      7.90 |         20207
    903 |   9003 |      8.30 |        202778
    906 |   9005 |      8.20 |        484746
    924 |   9006 |      7.30 |
    908 |   9007 |      8.60 |        779489
    909 |   9008 |           |        227235
    910 |   9009 |      3.00 |        195961
    911 |   9010 |      8.10 |        203875
    912 |   9011 |      8.40 |
    914 |   9013 |      7.00 |        862618
    915 |   9001 |      7.70 |        830095
    916 |   9014 |      4.00 |        642132
    925 |   9015 |      7.70 |         81328
    918 |   9016 |           |        580301
    920 |   9017 |      8.10 |        609451
    921 |   9018 |      8.00 |        667758
    922 |   9019 |      8.40 |        511613
    923 |   9020 |      6.70 |         13091

Sample Solution:

-- Selecting distinct movie titles from the 'movie' table
-- Using a subquery to find mov_id from the 'movie' table based on a condition
-- Specifically, finding mov_id where it is not in the set of mov_id from the 'Rating' table
SELECT DISTINCT mov_title 
FROM movie 
WHERE mov_id IN (
  -- Subquery to find mov_id not present in the 'Rating' table
  SELECT mov_id 
  FROM movie 
  WHERE mov_id NOT IN (
    SELECT mov_id 
    FROM Rating
  )
);

Sample Output:

                     mov_title
----------------------------------------------------
 Deliverance
 Amadeus
 Spirited Away
 The Prestige
 The Deer Hunter
 Eyes Wide Shut
 Back to the Future
 The Shawshank Redemption
 Seven Samurai
(9 rows)

Code Explanation:

The said query in SQL which selects distinct movie titles from the 'movie' table where the corresponding movie IDs are not present in the 'Rating' table. The results are ordered by movie title in ascending order.
The query uses a subquery to find the movie IDs that are not present in the 'Rating' table, and then selects the distinct movie titles corresponding to those IDs. The "DISTINCT" keyword ensures that only unique movie titles are returned.

Alternative Solutions:

Using LEFT JOIN and NULL Check:

SELECT DISTINCT m.mov_title
FROM movie m
LEFT JOIN rating r ON m.mov_id = r.mov_id
WHERE r.mov_id IS NULL;

Explanation:

This solution uses a LEFT JOIN to combine the movie and rating tables based on mov_id. It then filters the result to only include movies where there is no corresponding record in the rating table, effectively finding movies without ratings.

Using NOT EXISTS:

SELECT DISTINCT m.mov_title
FROM movie m
WHERE NOT EXISTS (
    SELECT 1
    FROM rating r
    WHERE r.mov_id = m.mov_id
);

Explanation:

This solution employs the NOT EXISTS clause to check if there is no corresponding record in the rating table for each movie in the movie table. If there is no match, the movie's mov_title is included in the result set.

Using NOT IN Subquery:

SELECT DISTINCT mov_title
FROM movie
WHERE mov_id NOT IN (
    SELECT mov_id
    FROM rating
);

Explanation:

This solution uses a subquery with NOT IN to find movies whose mov_id is not present in the list of mov_id values from the rating table, effectively identifying movies without ratings.

Practice Online

Query Visualization:

Duration:

Rows:

Cost:

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Previous: From the following tables, write a SQL query to find those years, which produced at least one movie and that, received a rating of more than three stars. Sort the result-set in ascending order by movie year. Return movie year.
Next: From the following tables, write a SQL query to find those reviewers who have rated nothing for some movies. Return reviewer name.