在 SQL 中使用复杂子查询进行练习

Question

我正在尝试在 SQL 中进行查询。该数据库是IMBD的一个。这是表格：

所以，我需要电影《低俗小说》(id=2175869) 中的 actors/actress，它从未与另一位低俗小说的演员/女演员在其他电影中合作过。

应该是这样的：

SELECT person_id FROM cast_info WHERE movie_id = 2175869 AND
person_id NOT IN (SELECT )

但是我不知道如何做第二部分。

Answer 1

稍后用作子查询的查询，返回除 Pulp Fiction 以外的电影，其中有不止一位 Pulp Fiction 演员在其中演出

SELECT movie_id
FROM cast_info
WHERE
    movie_id <> 2175869 AND
    person_id IN (SELECT person_id FROM cast_info WHERE movie_id = 2175869)
GROUP BY movie_id
HAVING COUNT(*) > 1

现在让从未在此类电影中出演过《低俗小说》的人加入

SELECT person_id
FROM cast_info
WHERE
    movie_id = 2175869 AND
    person_id NOT IN (
        SELECT person_id FROM cast_info WHERE movie_id IN (
            SELECT movie_id
            FROM cast_info
            WHERE
                movie_id <> 2175869 AND
                person_id IN (SELECT person_id FROM cast_info WHERE movie_id = 2175869)
            GROUP BY movie_id
            HAVING COUNT(*) > 1
        )
    )

注意：我假设每部电影只能选派一位演员一次。如果同一演员可以在同一部电影中担任不同角色，则将 COUNT(*) 替换为 COUNT(DISTINCT person_id)。

Answer 2

首先你需要看到低俗小说中的所有演员：

SELECT person_id  as pulp_actor_id
FROM cast_info
WHERE movie_id = 2175869

然后你需要找到所有的演员组合：

SELECT c1.person_id as actor1_id
       c2.person_id as actor2_id
FROM cast_info c1
JOIN cast_info c2
  ON c1.person_id < c2.person_id
WHERE c1.movie_id = 2175869
  AND c2.movie_id = 2175869;

找到除低俗小说之外所有二人组合作的电影。

SELECT actor1_id, actor2_id, actor1_movies.movie_id
FROM (SELECT c1.person_id as actor1_id
             c2.person_id as actor2_id
      FROM cast_info c1
      JOIN cast_info c2
        ON c1.person_id < c2.person_id
      WHERE c1.movie_id = 2175869
        AND c2.movie_id = 2175869) as duos
JOIN cast_info as actor1_movies
  ON duos.actor1_id = actor1_movies.person_id
 AND actor1.movie_id <> 2175869
LEFT JOIN cast_info actor2_movies
  ON duos.actor2_id = actor2_movies.person_id
 AND actor1_movies.movie_id = actor2_movies.movie_id
WHERE actor2.movie_id IS NOT NULL;

现在获取不在最后结果中的低俗小说中的所有演员

SELECT person_id as pulp_actor_id
FROM cast_info c
LEFT JOIN ( SELECT actor1_id, actor2_id, actor1_movies.movie_id
            FROM (SELECT c1.person_id as actor1_id
                         c2.person_id as actor2_id
                  FROM cast_info c1
                  JOIN cast_info c2
                    ON c1.person_id < c2.person_id
                  WHERE c1.movie_id = 2175869
                    AND c2.movie_id = 2175869) as duos
            JOIN cast_info as actor1_movies
              ON duos.actor1_id = actor1_movies.person_id
             AND actor1.movie_id <> 2175869
            LEFT JOIN cast_info actor2_movies
              ON duos.actor2_id = actor2_movies.person_id
             AND actor1_movies.movie_id = actor2_movies.movie_id
            WHERE actor2.movie_id IS NOT NULL;
            WHERE movie_id = 2175869 ) as duos
  ON c.person_id IN ( actor1_id, actor2_id )
WHERE duos.movie_id IS NULL

在 SQL 中使用复杂子查询进行练习

Exercise in SQL with complex subquery

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