php - 仅获得相同的结果出现在 SQL 中

Question

这是我的代码，稍后我会将其放入 php 中，但目前我在提供的查询测试器中使用它。我们正在做一级凯文培根而不是六级。

我的查询如下：

SELECT name,year
FROM actors
JOIN roles ON roles.actor_id = actors.id
JOIN movies ON movies.id=roles.movie_id
WHERE actors.first_name= 'kevin' AND actors.last_name='bacon' OR actors.first_name= 'sean' AND actors.last_name='penn'
ORDER BY movies.name;

结果是

Animal House 1978
Apollo 13 1995 
Few Good Men, A 1992 
Footloose 1984 
Hollow Man 2000 
JFK 1991 
Mystic River 2003 
Mystic River 2003 
Planes, Trains & Automobiles 1987 
Stir of Echoes 1999 

如何让它只显示神秘河？

Answer 1

如果我正确理解了您的问题，则您正在尝试查找其中包含的电影Sean Penn列表Kevin Bacon。如果是这样，那么您将需要在查询中使用两次演员和角色表。

SELECT
    movies.name,
    movies.year
FROM
    actors AS actor2 INNER JOIN roles AS role2 ON actor2.ID = role2.actor_id
           INNER JOIN actors AS actor1 INNER JOIN roles AS role1 ON actor1.ID = role1.actor_id
                INNER JOIN movies ON role1.movie_id = movies.ID ON role2.movie_id = movies.ID
WHERE
    actor1.first_name= 'kevin' AND actor1.last_name='bacon'
        AND
    actor2.first_name= 'sean' AND actor2.last_name='penn'
ORDER BY movies.name;

Answer 2

一、分组条件

WHERE (actors.first_name= 'kevin' AND actors.last_name='bacon') OR 
      (actors.first_name= 'sean' AND actors.last_name='penn')

二、DISTINCT在SELECT关键字后面加

SELECT DISTINCT ...

后续问题：你为什么只想展示Mystic River？

Answer 3

我认为你在这里要求的是不同的......

DISTINCT 关键字可用于仅返回不同（不同）的值。

尝试这个

SELECT DISTINCT name,year
FROM actors
JOIN roles ON roles.actor_id = actors.id
JOIN movies ON movies.id=roles.movie_id
WHERE (actors.first_name= 'kevin' AND actors.last_name='bacon') OR (actors.first_name= 'sean' AND actors.last_name='penn')
ORDER BY movies.name;

和 THIS 在 where 子句中，

 WHERE (actors.first_name= 'kevin' AND actors.last_name='bacon') AND (actors.first_name= 'sean' AND actors.last_name='penn')

如果你想知道凯文培根和肖恩潘在同一部电影中的位置

Answer 4

尝试这个

SELECT DISTINCT name,year
FROM actors
JOIN roles ON roles.actor_id = actors.id
JOIN movies ON movies.id=roles.movie_id
WHERE actors.first_name= 'kevin' AND actors.last_name='bacon' OR actors.first_name= 'sean' AND actors.last_name='penn'
ORDER BY movies.name;