※ 引述《hochengyuan (阿渊)》之铭言：
: （针对 SQL 语言的问题，用这个标题。请用 Ctrl+Y 砍掉这行）
: 数据库名称： SQL SERVER
: 数据库版本： 2012
1. 列出所有和Steven Spielberg合作过的演员
//Steven Spielberg是导演 (directors)
select distinct a.first_name+' '+ a.last_name //好几个重复的演员 so distinct
from directors as d
left join movie_dirtctors as md on d.id = md.director_id
left join movies as m on md.movie_id = m.id
left join roles as r on m.id = r.movie_id
left join actors as a on r.actor_id = a.id
where d.first_name = 'Steven'
and d.last_name = 'Spielberg'
;
2. 计算Steven Spielberg执导的电影的平均RANKS
//平均AVG
select AVG(m.rank)
from directors as d
left join movie_dirtctors as md on d.id = md.director_id
left join movies as m on md.movie_id = m.id
where d.first_name = 'Steven'
and d.last_name = 'Spielberg'
;
3. 列出Sean Connery出现的电影类别(GENRE)，并且统计次数后降幂排列
select mg.genre,count(mg.genre)
from actor as a
left join roles as r on a.id = r.actor_id
left join movies as m on r.movie_id = m.id
left join movies_genres as mg on m.id = mg.movie_id
where a.first_name = 'Sean'
and a.last_name = 'Connery'
group by mg.genre
order by count(mg.genre) desc
;
4. 计算每个演员平均的RANKING，并且降幂排列之
其实是我买新键盘 试一下打SQL手感如何 觉得不太好用 帮QQ
SQL很简单啦 主key串在一起 就可以去别的资料表查资料了咩
思路就是相当于填一份“申请书” 想要什么字段就按照格式写下来
留一题给你自己写囉