MySQL - 查找演員一起工作過的其他演員

Question

我不知道如何在標題中解釋這個問題，所以我會給你一個電影和演員的例子。

我有三個表（表名 - 字段）：

actor - id, name 
movie - id, title 
actor_movie - actor_id, movie_id 

我想創造的是，在使用一個actor.id查詢的WHERE子句和輸出應該是誰的工作角色名單與這位演員合演電影。最好根據他們一起工作多少部電影來訂購。

編輯：這是我現在得到的，但它不顯示其他演員。它只能算演員157多少部電影已經在：

SELECT a.name, COUNT(m.title) movie_count 
FROM actor_movie 
JOIN actor 
ON actor.id = actor_movie.actor_id 
WHERE actor.id = 157 
GROUP BY actor.name 
ORDER BY movie_count DESC 

Answer 1

與演員選擇電影，由演員選擇電影中的其他演員，組和計數。

select a.id, a.name, count(*) 
from actor a 
join actor_movie am on am.actor_id = a.id 
where movie_id in (select movie_id from actor_movie where actor_id = @actor) 
and actor_id <> @actor -- remove this if you want to see how many movies the @actor has 
group by a.id 
order by count(*) desc; 

另一種方式來寫：

select a.id, a.name, counted.movies 
from actor a 
join 
(
    select actor_id, count(*) as movies 
    from actor_movie 
    where movie_id in (select movie_id from actor_movie where actor_id = @actor) 
    and actor_id <> @actor -- remove this if you want to see how many movies the @actor has 
    group by actor_id 
) counted on counted.actor_id = a.id 
order by count(*) desc; 

而另一個：

select 
    actor_id, 
    (select name from actor a where a.id = am.actor_id) as name, 
    count(*) as movies 
from actor_movie am 
where movie_id in (select movie_id from actor_movie where actor_id = @actor) 
and actor_id <> @actor -- remove this if you want to see how many movies the @actor has 
group by actor_id 
order by count(*) desc;