Question

select SUM(category) from film_list where title IN actors;

我被困了，我正在研究sakila数据库，而我正试图弄清楚电影类别中有55到65部电影。返回这些名称类别和每个类别的电影数量，按电影数量排序。请问有什么想法吗？

Answer 1

我认为你需要一个小组并且有

select category, count(*) as num_film
from film_list
group by category 
having num_film BETWEEN 55 AND 65
order by num_fim

Answer 2

试试这个

SELECT category, Count(*) AS FilmsCount
FROM Film_List
GROUP BY Category
HAVING Count(*) BETWEEN 55 AND 65
ORDER BY FilmsCount

Answer 3

猜测：

SELECT category, COUNT(*) AS films_per_category
  FROM film_list
 GROUP BY category
HAVING COUNT(*) BETWEEN 55 AND 65
 ORDER BY films_per_category

但是，如果您提供大纲架构和一些示例数据，那么就不会猜测。当然，我们不希望看到55行，但出于演示目的，5到6行之间可以正常工作。

Answer 4

这称为子查询：

select sum(category)
from film_list
where title IN (SELECT title FROM actors);

Answer 5

尝试此操作，它将回答以下查询： -查找包含55到65部电影的所有电影类别。返回这些名称类别和每个类别的电影数量，按电影数量排序。

SELECT 
    category.name,
    COUNT(fc.category_id) AS `Movies per Category`
FROM
    film_category AS fc
        JOIN
category ON fc.category_id = category.category_id
GROUP BY fc.category_id
HAVING `Movies per Category` BETWEEN 65 AND 75
ORDER BY `Movies per Category` DESC;

Answer 6

尝试使用Between运算符

 SELECT category, COUNT(*) AS films_per_category
 FROM film_list
 ORDER BY films_per_category
 HAVING COUNT(*) BETWEEN 55 AND 65

SQL。我坚持这个SQL查询

6 个答案: