如何在Oracle中运行SQL时创建临时/动态/虚拟表？

Question

我有一些必须测量的数据,这些数据不在任何表格中.我无法将其插入表中,也无法创建任何表并插入这些数据.所以我使用了以下两个来获取该表.我用它来加入其他表.

with movie_genre as
(
select '10' as "id", 'action' as "genre" from dual
union select '20' as "id", 'horror' as "genre" from dual
union select '30' as "id", 'comedy' as "genre" from dual
union select '40' as "id", 'adventure' as "genre" from dual
union select '50' as "id", 'drama' as "genre" from dual
union select '60' as "id", 'mystery' as "genre" from dual
union select '70' as "id", 'musical' as "genre" from dual
)
select * from movie_genre
;

所以我得到了结果 -

id  genre
10  action
20  horror
30  comedy
40  adventure
50  drama
60  mystery
70  musical

我的问题是,有没有更好的方法来做到这一点？任何建议都将是一个救生员.

一个例子 -

让我们说我们有一张桌子 -

create table movies (
id number,
name varchar2(50),
genre_id number
);

insert into movies values (1, 'the hulk', 10);
insert into movies values (2, 'dumb and dumber', 30);
insert into movies values (3, 'frozen', 70);

我们需要这样的结果 -

name                genre        is_in_genre
the hulk            action       yes
the hulk            horror       no
the hulk            comedy       no
the hulk            adventure    no
the hulk            drama        no
the hulk            mystery      no
the hulk            musical      no
dumb and dumber     action       no
dumb and dumber     horror       no
dumb and dumber     comedy       yes
dumb and dumber     adventure    no
dumb and dumber     drama        no
dumb and dumber     mystery      no
dumb and dumber     musical      no
frozen              action       no
frozen              horror       no
frozen              comedy       no
frozen              adventure    no
frozen              drama        no
frozen              mystery      no
frozen              musical      yes

在这里,我们没有任何movie_genre表.

Answer 1

您可以按照您想要的顺序将类型作为字符串传递,并使用正则表达式生成movie_genre表.sql在这里小提琴

with movie_genre as
( 
 select level * 10 as id, regexp_substr(genre,'[^,]+',1,level) as genre
 from
 (
  select ('action,horror,comedy,adventure,drama,mystery,musical') 
  as genre from dual
  )
  connect by level <=REGEXP_COUNT(genre,'[^,]+')
 )
 select * from movie_genre;