如何从使用第三个表SQL Server相关的两个表中检索数据

时间:2014-08-23 15:05:40

标签: sql-server

我有三张桌子(简化)

movie(id int primary key identity, title varchar(20) not null)
genre(id int primary key identity, type varchar(10) not null)

movie_genre(movie_id int references movie(id), 
            genre_id int references genre(id), 
            primary key(movie_id, genre_id))

电影中的数据

id          title
---------------------------
1     |     Inception
2     |     The Dark Knight

流派中的数据

id          type 
---------------------
1     |     action 
2     |     adventure 
3     |     thriller

movie_genre中的数据

movie_id          genre_id 
----------------------------
1               |     1 
1               |     2 
2               |     1 
2               |     3 

我想在一列中显示其类型类型的电影名称。所以,输出将是

title              |     genres 
-----------------------------------------
Inception          |     action adventure 
The Dark Knight    |     action thriller

我试着这样做

select 
    movie.title, genre.type 
from 
    movie, genre 
where 
    movie.id = movie_genre.movie_id 
    and genre.id = movie_genre.genre_id;

但它说:

  

无法绑定多部分标识符“movie_genre.movi​​e_id”   无法绑定多部分标识符“movie_genre.genre_id”。

我对SQL很新,任何帮助都会受到赞赏。

编辑:
使用

SELECT G.[Type] ,M.[Title]
FROM movie_genre MG  
LEFT JOIN genre G ON MG.genre_id = G.ID
LEFT JOIN movie M ON MG.Movie_ID = M.ID

select movie.title, genre.type 
from movie, genre, movie_genre
where
movie.id = movie_genre.movie_id 
and genre.id = movie_genre.genre_id;

现在是输出,

    title              |     genres 
-----------------------------------------
Inception          |     action
Inception          |     adventure 
The Dark Knight    |     action
The Dark Knight    |     thriller

我如何在一行中显示流派?

2 个答案:

答案 0 :(得分:3)

SELECT G.[Type] 
       ,M.[Title]
FROM movie_genre MG  
LEFT JOIN genre G ON MG.genre_id = G.ID
LEFT JOIN movie M ON MG.Movie_ID = M.ID

获取列表

SELECT DISTINCT M.[Title]
      ,STUFF((
           SELECT ' ' + G.[Type] 
           FROM genre G INNER JOIN movie_genre MG
           ON  MG.genre_id = G.ID
           WHERE MG.Movie_id = Mov.Movie_id
           FOR XML PATH(''),TYPE)
            .value('.','NVARCHAR(MAX)'),1,1, '') Genre
FROM movie_genre Mov  
INNER JOIN movie M ON Mov.Movie_ID = M.ID

或者

SELECT DISTINCT M.[Title]
      ,STUFF(List,1,1, '') Genre
FROM @movie_genre Mov  
INNER JOIN @movie M 
ON Mov.Movie_ID = M.ID
             CROSS APPLY 
                       (
                       SELECT ' ' + G.[Type] 
                       FROM @genre G INNER JOIN @movie_genre MG
                       ON  MG.genre_id = G.ID
                       WHERE MG.Movie_id = Mov.Movie_id
                       FOR XML PATH('')
                       )Gen(List)

SQL FIDDLE

答案 1 :(得分:-2)

我相信你需要将'movie_genre'添加到FROM,例如:

SELECT movie.title, genre.type FROM (movie, genre, movie_genre) WHERE ....