Oracle SQL - 如何在一行中显示一对多关系？

Question

我有一个名为MY_MOVIES的表,有两列:MOVIES和GENRES就像这样(关系是一部电影到很多类型):

GENRE         MOVIE
----------    --------------           
ACTION        MOVIE1
DRAMA         MOVIE1
CRIME         MOVIE2
DRAMA         MOVIE2
CRIME         MOVIE3
DRAMA         MOVIE3
ACTION        MOVIE4
ADVENTURE     MOVIE4
FANTASY       MOVIE4
ANIMATION     MOVIE5
ADVENTURE     MOVIE5
COMEDY        MOVIE5

该表有超过100000行.

我想要得到这样的输出:

MOVIES        GENRES
----------    -------------- 
MOVIE1        ACTION, DRAMA
MOVIE2        CRIME, DRAMA
MOVIE3        CRIME, DRAMA
MOVIE4        ACTION, ADVENTURE, FANTASY
MOVIE5        ANIMATION, ADVENTURE, COMEDY

我正在尝试使用像这样的PIVOT(有了将0和1替换为类型的想法):

SELECT * FROM MY_MOVIES 
PIVOT (COUNT(MOVIE) FOR GENRE in (SELECT DISTINCT(GENRE) FROM MY_MOVIES) as MOVIE_GENRES

我一直以为我做错了.

Answer 1

假设您使用的是Oracle(版本11gR2或更高版本):

select movies,
       listagg(genre, ', ') within group (order by genre) as genres
from my_movies
group by movies;