使用MySQL查询IMDB数据库
我编写了一个SQL查询来回答以下问题: 在IMBD数据库中查找所有与Yash Chopra合作制作的电影比其他任何导演都多的演员 示例架构:使用MySQL查询IMDB数据库,mysql,imdb,Mysql,Imdb,我编写了一个SQL查询来回答以下问题: 在IMBD数据库中查找所有与Yash Chopra合作制作的电影比其他任何导演都多的演员 示例架构: person (pid * ,name ); m_cast (mid * ,pid * ); m_director (mid* ,pid* ); * = (component of) PRIMARY KEY 以下是我的疑问: WITH common_actors AS (SELECT A.actor_id as actors, B
person
(pid *
,name
);
m_cast
(mid *
,pid *
);
m_director
(mid*
,pid*
);
* = (component of) PRIMARY KEY
以下是我的疑问:
WITH common_actors AS
(SELECT A.actor_id as actors, B.director_id as director_id, B.movies as movies_with_director,
B.director_id as yash_chops_id, B.movies as movies_with_yash_chops FROM
(SELECT M_Cast.PID as actor_id, M_Director.PID as director_id, COUNT(*) as movies from M_Cast
left join M_Director
ON M_Cast.MID = M_Director.MID
GROUP BY actor_id, director_id) A
JOIN
(SELECT M_Cast.PID as actor_id, M_Director.PID as director_id, COUNT(*) as movies from M_Cast
left join M_Director
ON M_Cast.MID = M_Director.MID
GROUP BY actor_id, director_id
)B
ON A.actor_id = B.actor_id
WHERE B.director_id in (SELECT PID FROM Person WHERE Name LIKE
'%Yash%Chopra%'))
SELECT distinct actors as actor_id, movies_with_yash_chops as total_movies FROM common_actors
WHERE actors NOT IN (SELECT actors FROM common_actors WHERE movies_with_director > movies_with_yash_chops)
从中得到的结果是长度:430行。但是,获得的结果应为243行。谁能告诉我我的问题哪里出错了?我的方法正确吗
样本结果:
Actor name
0 Sharib Hashmi
1 Kulbir Badesron
2 Gurdas Maan
3 Parikshat Sahni
...
242 Ramlal Shyamlal
提前谢谢 考虑以下几点:
DROP TABLE IF EXISTS person;
CREATE TABLE person
(person_id SERIAL PRIMARY KEY
,name VARCHAR(20) NOT NULL UNIQUE
);
DROP TABLE IF EXISTS movie;
CREATE TABLE movie
(movie_id SERIAL PRIMARY KEY
,title VARCHAR(50) NOT NULL UNIQUE
);
DROP TABLE IF EXISTS m_cast;
CREATE TABLE m_cast
(movie_id INT NOT NULL
,person_id INT NOT NULL
,PRIMARY KEY(movie_id,person_id)
);
DROP TABLE IF EXISTS m_director;
CREATE TABLE m_director
(movie_id INT NOT NULL
,person_id INT NOT NULL
,PRIMARY KEY(movie_id,person_id)
);
INSERT INTO person (name) VALUES
('Steven Feelberg'),
('Manly Kubrick'),
('Alfred Spatchcock'),
('Fred Pitt'),
('Raphael DiMaggio'),
('Bill Smith');
INSERT INTO movie VALUES
(1,'Feelberg\'s Movie with Fred & Raph'),
(2,'Feelberg and Fred Ride Again'),
(3,'Kubrick shoots DiMaggio'),
(4,'Kubrick\'s Movie with Bill Smith'),
(5,'Spatchcock Presents Bill Smith');
INSERT INTO m_director VALUES
(1,1),
(2,1),
(3,2),
(4,2),
(5,3);
INSERT INTO m_cast VALUES
(1,4),
(1,5),
(2,4),
(3,5),
(4,6),
(5,6);
我把电影表放进去只是为了便于参考。这与实际问题无关。
此外,请注意,此模型假设演员只列出一次,而不管他们在给定电影中是否有多个角色
下面的查询询问“每个演员和导演多久一起工作一次”
演员是任何一部电影的演员。
导演是指任何一部电影的导演
SELECT a.name actor
, d.name director
, COUNT(DISTINCT ma.movie_id) total
FROM person d
JOIN m_director md
ON md.person_id = d.person_id
JOIN person a
LEFT
JOIN m_cast ma
ON ma.person_id = a.person_id
AND ma.movie_id = md.movie_id
JOIN m_cast x
ON x.person_id = a.person_id
GROUP
BY actor
, director;
+-------------------+-------------------+-------+
| actor | director | total |
+-------------------+-------------------+-------+
| Fred Pitt | Alfred Spatchcock | 0 |
| Fred Pitt | Manly Kubrick | 0 |
| Fred Pitt | Steven Feelberg | 2 |
| Raphael DiMaggio | Alfred Spatchcock | 0 |
| Raphael DiMaggio | Manly Kubrick | 1 |
| Raphael DiMaggio | Steven Feelberg | 1 |
| Bill Smith | Alfred Spatchcock | 1 |
| Bill Smith | Manly Kubrick | 1 |
| Bill Smith | Steven Feelberg | 0 |
+-------------------+-------------------+-------+
通过观察,我们可以看到:
唯一一位与费尔伯格合作次数最多的演员是弗雷德·普里特
拉斐尔·迪卡普里奥(Raphael DiCaprio)和比尔·史密斯(Bill Smith)都曾与两位董事进行过同样频繁的合作,尽管他们的董事不同
编辑:虽然我不是认真地提倡将此作为一种解决方案,但下面只是简单地说明,上面提供的内核确实是解决问题所需的全部
SELECT x.*
FROM
( SELECT a.*
FROM
( SELECT a.name actor
, d.name director
, COUNT(DISTINCT ma.movie_id) total
FROM person d
JOIN m_director md
ON md.person_id = d.person_id
JOIN person a
LEFT
JOIN m_cast ma
ON ma.person_id = a.person_id
AND ma.movie_id = md.movie_id
JOIN m_cast x
ON x.person_id = a.person_id
GROUP
BY actor
, director
) a
LEFT
JOIN
( SELECT a.name actor
, d.name director
, COUNT(DISTINCT ma.movie_id) total
FROM person d
JOIN m_director md
ON md.person_id = d.person_id
JOIN person a
LEFT
JOIN m_cast ma
ON ma.person_id = a.person_id
AND ma.movie_id = md.movie_id
JOIN m_cast x
ON x.person_id = a.person_id
GROUP
BY actor
, director
) b
ON b.actor = a.actor
AND b.director <> a.director
AND b.total > a.total
WHERE b.actor IS NULL
) x
LEFT JOIN
( SELECT a.*
FROM
( SELECT a.name actor
, d.name director
, COUNT(DISTINCT ma.movie_id) total
FROM person d
JOIN m_director md
ON md.person_id = d.person_id
JOIN person a
LEFT
JOIN m_cast ma
ON ma.person_id = a.person_id
AND ma.movie_id = md.movie_id
JOIN m_cast x
ON x.person_id = a.person_id
GROUP
BY actor
, director
) a
LEFT
JOIN
( SELECT a.name actor
, d.name director
, COUNT(DISTINCT ma.movie_id) total
FROM person d
JOIN m_director md
ON md.person_id = d.person_id
JOIN person a
LEFT
JOIN m_cast ma
ON ma.person_id = a.person_id
AND ma.movie_id = md.movie_id
JOIN m_cast x
ON x.person_id = a.person_id
GROUP
BY actor
, director
) b
ON b.actor = a.actor
AND b.director <> a.director
AND b.total > a.total
WHERE b.actor IS NULL
) y
ON y.actor = x.actor AND y.director <> x.director
WHERE y.actor IS NULL;
+-----------+-----------------+-------+
| actor | director | total |
+-----------+-----------------+-------+
| Fred Pitt | Steven Feelberg | 2 |
+-----------+-----------------+-------+
这将返回每个演员的列表,以及他们最常合作的导演。在这种情况下,由于比尔·史密斯和拉斐尔·迪马吉奥通常与两位董事平起平坐,他们被排除在结果之外
你的问题的答案就是从这个列表中选择Yash Chopra列为导演的所有行。嘿,谢谢你的回答,但是如果你看到我写的查询,我已经列出了每个可能的演员-导演组合及其电影总数,问题是,我真的很困惑,如何找到与某位导演合作的电影比其他任何导演都多的演员。在我的例子中,我自己加入了这个表,条件是正确的表中只有那个特定的导演,这样我就可以得到所有和其他导演一起制作更多电影的演员,并将他们过滤掉,因此剩下的演员将是我们的答案。我现在明白了!非常感谢你抽出时间回答这个问题。我如何接受这个答案对不起,我很笨,不过我没有投票!