Question

有人能告诉我为什么我的解决方案不能应对这一挑战吗？

http://sqlzoo.net/wiki/More_JOIN_operations

15。列出1978年发布的电影，按演员阵容的数量排序，然后按标题排列。

SELECT title, COUNT(actorid) AS actors FROM movie
JOIN casting ON id = movieid
WHERE yr = 1978
GROUP BY title
ORDER BY actors DESC

Answer 1

因为您错过了第二级ORDER BY字词。它应该是：

ORDER BY actors DESC, title

（问题并没有明确要求降序，但他们的官方“正确答案”是这样订购的。）

Answer 2

由于要求要求您按演员数量和标题排序。因此，您必须在title子句中添加Order by：

SELECT title, COUNT(actorid) AS actors FROM movie
 JOIN casting ON id = movieid
 WHERE yr = 1978
 GROUP BY title
 ORDER BY actors DESC, title

Answer 3

select distinct a1.name from actor a1
join casting c1 on c1.actorid = a1.id
join movie m1 on c1.movieid = m1.id
where m1.id in (
select distinct m.id from movie m
join casting c on c.movieid = m.id
join actor a  on c.actorid = a.id
where a.name = 'Art Garfunkel')
and a1.name <> 'Art Garfunkel'

sqlzoo＆＃34;更多加入＆＃34; ＃15

3 个答案: