【发布时间】:2011-07-25 06:47:28
【问题描述】:
以下是表结构。
- tbl_movie_master (movie_id,title)
- tbl_genre_master (genre_id,genre)
- tbl_movie_genre (movie_id,genre_id)
一部电影可以映射多种流派,所以tbl_movie_genre的情况下存在多对多关系。
我有电影详细信息页面,我在其中获取电影 ID。我必须编写查询来完成以下任务。
我必须找到与给定电影 ID 匹配的所有类型的电影。
例如我有电影 ID 45,这部电影属于喜剧和浪漫类型,然后我必须找到所有其他类型为喜剧和浪漫的电影。不应填充只有喜剧或只有爱情的电影。
是否可以在单个查询中完成?
更新:
在以下示例中,只有前 2 部电影满足条件。 “Hum tum ke pyar”和“housefull”。
drop table if exists tbl_movie_master, tbl_genre_master, tbl_movie_genre ;
create table tbl_movie_master (movie_id int, title varchar(100));
insert into tbl_movie_master values (1, 'Hum tum ke pyar'), (2, 'housefull'), (3, 'ek vakta ke liye'), (4, 'chalo pyar kare');
create table tbl_genre_master (genre_id int, genre varchar(100));
insert into tbl_genre_master values (1, 'horror'), (2, 'remoance'), (3, 'suspense'), (4, 'social');
create table tbl_movie_genre (movie_id int, genre_id int);
insert into tbl_movie_genre values (1, 1), (1, 2), (2, 1), (2, 2), (3, 3), (4, 1), (4,4);
mysql> select * from tbl_movie_master;
+----------+------------------+
| movie_id | title |
+----------+------------------+
| 1 | Hum tum ke pyar |
| 2 | housefull |
| 3 | ek vakta ke liye |
| 4 | chalo pyar kare |
+----------+------------------+
4 rows in set (0.00 sec)
mysql> select * from tbl_genre_master;
+----------+----------+
| genre_id | genre |
+----------+----------+
| 1 | horror |
| 2 | remoance |
| 3 | suspense |
| 4 | social |
+----------+----------+
4 rows in set (0.00 sec)
mysql> select * from tbl_movie_genre;
+----------+----------+
| movie_id | genre_id |
+----------+----------+
| 1 | 1 |
| 1 | 2 |
| 2 | 1 |
| 2 | 2 |
| 3 | 3 |
| 4 | 1 |
| 4 | 4 |
+----------+----------+
7 rows in set (0.00 sec)
SELECT m.*
FROM tbl_movie_master m
JOIN tbl_movie_genre mg ON mg.movie_id = m.movie_id
WHERE mg.genre_id = ALL (SELECT mg.genre_id FROM tbl_movie_genre mg WHERE mg.movie_id = 1);
Empty set (0.00 sec)
SELECT m.title
FROM tbl_movie_master m
JOIN tbl_movie_genre allgenres
ON m.movie_id= allgenres.movie_id
JOIN
(SELECT genre_id FROM tbl_movie_genre WHERE movie_id=1) somegenres
ON somegenres.genre_id=allgenres.genre_id;
+-----------------+
| title |
+-----------------+
| Hum tum ke pyar |
| Hum tum ke pyar |
| housefull |
| housefull |
| chalo pyar kare |
+-----------------+
5 rows in set (0.00 sec)
SELECT M.`title`, G.`genre`, M2.`title`
FROM tbl_movie_master AS M, tbl_movie_genre AS A
LEFT JOIN tbl_movie_master AS M2 ON A.`movie_id` = M2.`movie_id`
LEFT JOIN tbl_genre_master AS G ON A.`genre_id` = G.`genre_id`
WHERE M.`movie_id` = 1;
+-----------------+----------+------------------+
| title | genre | title |
+-----------------+----------+------------------+
| Hum tum ke pyar | horror | Hum tum ke pyar |
| Hum tum ke pyar | remoance | Hum tum ke pyar |
| Hum tum ke pyar | horror | housefull |
| Hum tum ke pyar | remoance | housefull |
| Hum tum ke pyar | suspense | ek vakta ke liye |
| Hum tum ke pyar | horror | chalo pyar kare |
| Hum tum ke pyar | social | chalo pyar kare |
+-----------------+----------+------------------+
7 rows in set (0.00 sec)
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标签: mysql