Question

我有三个表存储桶（类别），帖子，评论而且我想获得具有15条以上评论的类别中的帖子数

我正在尝试以下查询：

SELECT buckets.`id`,buckets.`name`,COUNT(comment.`post_id`) AS comment_count 
FROM post
LEFT JOIN `comment` ON comment.`post_id` = post.`id`
INNER JOIN `buckets` ON buckets.`id` = post.`bucket`
GROUP BY comment.`post_id` 
HAVING COUNT(buckets.`id`) > 14 ORDER BY buckets.`id`

预期结果

+----+---------+------------+---------------+
| ID | NAME    | POST_COUNT | COMMENT_COUNT |
+----+---------+------------+---------------+
| 1  | Bucket1 | 3          | 70            |
+----+---------+------------+---------------+
| 2  | Bucket2 | 2          | 80            |
+----+---------+------------+---------------+
| 3  | Bucket3 | 4          | 90            |
+----+---------+------------+---------------+
| 4  | Bucket4 | 0          | 15            |
+----+---------+------------+---------------+

Answer 1

我想获得包含15条以上评论的类别中的帖子数

您的问题表达不佳。将来请记住，如果表有明确说明，则回答表的问题会更容易。

很明显，您对帖子有评论。让我们得到15个或更多的那些。（您说的是“大于15”，但是查询要求输入> 14。

select post_id, count(*) as ncomment from comments
group by post_id
having count(*) > 14

现在我们可以按类别对帖子进行计数，并获得每个帖子的评论总数

select category, count(P.post_id) as npost, sum(N) as ncomment
from  from buckets as P
join (
    select post_id, count(*) as N
    from comments
    group by post_id
    having count(*) > 14
) as C
on P.post_id = C.post_id
group by category

Answer 2

我得到的查询不完全是我想要的，但使用group_concat有用

SELECT A.id，A.name，GROUP_CONCAT（A.comment_count SEPARATOR'，'）AS total_post FROM（SELECT buckets.id，buckets.name， COUNT（comment.post_id）AS comment_count FROM post INNER JOIN comment ON comment.post_id = post.id 内连接桶在buckets.id = post.bucket上 GROUP BY comment.post_id拥有COUNT（comment.post_id）> 14）A GROUP BY A.id，A.name

注意-> total_post是超过14条评论的帖子

id ----名称----- total_post
1 ---- H1B ------ 91、15、19、20、15、15、26、20、79
3 ---- I-140----- 28
4 ---- I-134（AP）----- 40，28，62
7 ---- MISC -------- 74，15

想要获得具有超过15条评论的类别的帖子

2 个答案: