SQL exercises on movie Database: Find the reviewer name, movie title, and number of stars for those movies which rating is the lowest one
14. From the following table, write a SQL query to find the movies with the lowest ratings. Return reviewer name, movie title, and number of stars for those movies.
Sample table: reviewerrev_id | rev_name --------+-------------------------------- 9001 | Righty Sock 9002 | Jack Malvern 9003 | Flagrant Baronessa 9004 | Alec Shaw 9005 | 9006 | Victor Woeltjen 9007 | Simon Wright 9008 | Neal Wruck 9009 | Paul Monks 9010 | Mike Salvati 9011 | 9012 | Wesley S. Walker 9013 | Sasha Goldshtein 9014 | Josh Cates 9015 | Krug Stillo 9016 | Scott LeBrun 9017 | Hannah Steele 9018 | Vincent Cadena 9019 | Brandt Sponseller 9020 | Richard AdamsSample table: rating
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 table: movie
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
Sample Solution:
-- Selecting reviewer names, movie titles, and review stars
-- Using the 'reviewer', 'movie', and 'rating' tables
-- Filtering rows where rating.rev_stars is equal to the minimum rev_stars
-- The subquery selects the minimum rev_stars from the 'rating' table
-- Joining tables based on rev_id and mov_id to get reviewer names and movie titles
SELECT reviewer.rev_name, movie.mov_title, rating.rev_stars
FROM reviewer, movie, rating
WHERE rating.rev_stars = (
SELECT MIN(rating.rev_stars)
FROM rating
)
AND rating.rev_id = reviewer.rev_id
AND rating.mov_id = movie.mov_id;
Sample Output:
rev_name | mov_title | rev_stars
--------------------------------+----------------------------------------------------+-----------
Paul Monks | Boogie Nights | 3.00
(1 row)
Code Explanation:
The said query in SQL that retrieves the names of reviewers who gave the lowest rating, the titles of movies that received the lowest rating, and the lowest rating itself.
the names of reviewers, the titles of movies, and the lowest ratings given by any reviewer for any movie in a database.
The query joins the tables reviewer, movie, and rating.
The query retrieves the rev_name from the reviewer table, the mov_title from the movie table, and the rev_stars from the rating table. It uses a subquery to find the minimum value of rev_stars from the rating table. It then selects the rows from the three tables where the rev_stars equals the minimum value found in the subquery, and the rev_id and mov_id in the rating table match the corresponding values in the reviewer and movie tables.
Alternative Solutions:
Using JOIN and Subquery:
SELECT r.rev_name, m.mov_title, ra.rev_stars
FROM reviewer r
JOIN rating ra ON r.rev_id = ra.rev_id
JOIN movie m ON m.mov_id = ra.mov_id
WHERE ra.rev_stars = (
SELECT MIN(rev_stars)
FROM rating
);
Explanation:
This query uses JOINs to combine the reviewer, rating, and movie tables based on their respective IDs. It then applies a WHERE clause to filter for ratings that have the minimum rev_stars using a subquery.
Using INNER JOIN and Subquery:
SELECT r.rev_name, m.mov_title, ra.rev_stars
FROM reviewer r
INNER JOIN rating ra ON r.rev_id = ra.rev_id
INNER JOIN movie m ON m.mov_id = ra.mov_id
WHERE ra.rev_stars = (
SELECT MIN(rev_stars)
FROM rating
);
Explanation:
This query also uses INNER JOINs to combine the tables and applies a WHERE clause to filter for ratings that have the minimum rev_stars using a subquery.
Using JOINs with ON Clause:
SELECT r.rev_name, m.mov_title, ra.rev_stars
FROM reviewer r
JOIN rating ra ON r.rev_id = ra.rev_id
JOIN movie m ON m.mov_id = ra.mov_id
WHERE ra.rev_stars = (
SELECT MIN(rev_stars)
FROM rating
);
Explanation:
This query explicitly specifies the join conditions using the ON clause. It then applies a WHERE clause to filter for ratings that have the minimum rev_stars using a subquery.
Practice Online
Query Visualization:
Duration:
Rows:
Cost:
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Previous: From the following tables, write a SQL query to find the movies, which have reviewed by any reviewer body except by 'Paul Monks'. Return movie title.
Next: From the following tables, write a SQL query to find the movies directed by ‘James Cameron’. Return movie title.
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