SQL:创建一个比较不同行的视图
我有这样一些电影的数据:SQL:创建一个比较不同行的视图,sql,join,count,sql-view,Sql,Join,Count,Sql View,我有这样一些电影的数据: cast_id | cast_name | movie_id 1 A 11 2 B 11 3 C 11 4 D 12 5 E 12 1 A 13 CREATE VIEW compare(cast_id_1, cast_id_2, num_movies);
cast_id | cast_name | movie_id
1 A 11
2 B 11
3 C 11
4 D 12
5 E 12
1 A 13
CREATE VIEW compare(cast_id_1, cast_id_2, num_movies);
SELECT * FROM compare LIMIT 1;
(1,2,2)
我想创建一个视图,在该视图中比较两个不同的演员阵容成员,以便从以下内容开始:
cast_id | cast_name | movie_id
1 A 11
2 B 11
3 C 11
4 D 12
5 E 12
1 A 13
CREATE VIEW compare(cast_id_1, cast_id_2, num_movies);
SELECT * FROM compare LIMIT 1;
(1,2,2)
我看的是演员A和演员B,他们一共有两部电影
我不知道如何比较这两个不同的行,我的搜索者到目前为止都没有成功。非常感谢您的帮助 这是一个自连接:
create view myview as
select t1.cast_id cast_id_1, t2.cast_id cast_id_2, count(*) num_movies
from mytable t1
inner join mytable t2 on t2.movie_id = t1.movie_id and t1.cast_id < t2.cast_id
group by t1.cast_id, t2.cast_id
我想做个手术可能会有帮助。此存储过程将2个cast_id和num_电影作为输入参数。它选择两位演员同时出演的电影的电影id。然后根据该数字是否超过num_movies参数:1)返回电影列表(发行日期、导演等),否则返回消息“两部电影不在一起”
drop proc if exists TwoMovieActors;
go
create proc TwoMovieActors
@cast_id_1 int,
@cast_id_2 int,
@num_movies int
as
set nocount on;
declare @m table(movie_id int unique not null,
rn int not null);
declare @rows int;
with
cast_cte as (
select *, row_number() over (partition by movie_id order by cast_name) rn
from movie_casts mc
where cast_id in(@cast_id_1, @cast_id_2))
insert @m
select movie_id, row_number() over (order by movie_id) rn
from cast_cte
where rn=2
select @rows=@@rowcount;
if @rows<@num_movies
select concat('Were not in ', cast(@num_movies as varchar(11)), ' movies together');
else
select m.movie_id, mv.movie_name, mv.release_date, mv.director
from @m m
join movies mv on m.movie_id=mv.movie_id;
你的数据库管理系统是什么?