获取最高用户排名位置取决于加入查询的最大数量

Question

取决于最高计数我想获得每个用户的排名。

以下是查询：

SELECT @a:=@a+1 serial_number, `tbl_users`.`user_id`, 
`tbl_users`.`first_name`,
`tbl_users`.`last_name`,
 COUNT(`tbl_qa_questions`.`question_id`) AS qs_count 
FROM `tbl_qa_questions`
LEFT JOIN `tbl_users` 
ON `tbl_qa_questions`.`user_id` = `tbl_users`.`user_id` 
, (SELECT @a:= 0) AS a
WHERE 1 AND DATE(`tbl_qa_questions`.`post_date`) BETWEEN '2015-01-01' AND '2015-01-19' 
AND `tbl_qa_questions`.`status` = 1  
GROUP BY `tbl_qa_questions`.`user_id`
ORDER BY qs_count DESC  LIMIT 5

显示结果

serial_number   user_id     first_name  last_name   qs_count
10              47          Sourav      Sen         26
11              32          Alan        Donald      15
9               587         Abraham     Harrison    2
8               586         Thomas      Broad       2
6               13          Sumanta     Sen         2

但它应该：

serial_number   user_id     first_name  last_name   qs_count
1               47          Sourav      Sen         26
2               32          Alan        Donald      15
3               587         Abraham     Harrison    2
4               586         Thomas      Broad       2
5               13          Sumanta     Sen         2
.
.
.
29              14          xyz         Sen         2
30              15          abc         Sen         2
31              16          cdf         Sen         2

即。每行的序列号应为1,2,3,4和5。

Answer 1

只需在外部查询中添加编号，即可嵌套聚合。问题是变量在 GROUP BY开始之前会增加，因此您会得到一些随机结果。实际上，当在SELECT中使用不在GROUP BY中的东西时，总是如此，特定于MySQL（其他DB只会给你错误）。

SELECT @a:=@a+1 serial_number, aa.* from (

sELECT
`tbl_users`.`first_name`,
`tbl_users`.`last_name`,
 COUNT(`tbl_qa_questions`.`question_id`) AS qs_count 
FROM `tbl_qa_questions`
LEFT JOIN `tbl_users` 
ON `tbl_qa_questions`.`user_id` = `tbl_users`.`user_id` 
, (SELECT @a:= 0) AS a
WHERE 1 AND DATE(`tbl_qa_questions`.`post_date`) BETWEEN '2015-01-01' AND '2015-01-19' 
AND `tbl_qa_questions`.`status` = 1  
GROUP BY `tbl_qa_questions`.`user_id`
ORDER BY qs_count DESC  LIMIT 5
) aa