Mysql 轨道计数选择不同

我正在记录用户观看一系列视频的次数。现在我正试图绘制一张每天观看任何视频的用户数量图表

UserVideoWatching.where("created_at >= ? AND user_id != ?",1.month.ago, User.elephant.id).group("DATE(created_at)").reorder('created_at').count

生成sql

SELECT COUNT(*) AS count_all, DATE(created_at) AS date_created_at FROM `user_video_watchings` WHERE (created_at >= '2013-01-27 10:43:24' AND user_id != 7) GROUP BY DATE(created_at) ORDER BY created_at

这将为每天观看的所有视频生成正确的结果，但正如我所说的，我只想向每个用户显示一次

我想要的sql是

SELECT COUNT(DISTINCT user_id) AS count_all, DATE(created_at) AS date_created FROM `user_video_watchings` WHERE (created_at >= '2013-01-27 10:33:18' AND user_id != 7) GROUP BY DATE(created_at) ORDER BY created_at

所以我想

UserVideoWatching.where("created_at >= ? AND user_id != ?",1.month.ago, User.elephant.id).group("DATE(created_at)").reorder('created_at').select('COUNT(DISTINCT user_id) AS count_all, DATE(created_at) AS date_created')

我会做我想做的事。但这给了

[#<UserVideoWatching >, #<UserVideoWatching >]

而不是一个杂烩

有什么想法吗

我使用的是rails 3.1和mysql，您可以使用distinct.count:attribute\u name

在Rails3中，使用：count:user\u id，而不是distinct:true

因此：

无法进行测试，但我认为这将产生您所追求的SQL。

在Rails 4中，使用…uniq.count:user\u id，如本问题的其他答案和其他地方所述，这实际上会导致查询中出现一个额外的独特存在：

从中选择DISTINCT COUNTDISTINCT user\u id

我们实际上要做的是自己使用SQL字符串：

..countDISTINCT用户标识

这给了我们：

---

选择COUNTDISTINCT user\u id FROM…

在rails 5.0.1中应使用distinct，distinct equal uniq，但

[11] pry(main)> Needremember.distinct.count(:word)
(1.1ms)  SELECT DISTINCT COUNT(DISTINCT "needremembers"."word") FROM "needremembers"
[12] pry(main)> Needremember.uniq.count(:word)
DEPRECATION WARNING: uniq is deprecated and will be removed from Rails 5.1 (use distinct instead) (called from __pry__ at (pry):12)
   (0.6ms)  SELECT DISTINCT COUNT(DISTINCT "needremembers"."word") FROM "needremembers"

---

rails 4中已弃用请参阅，了解使用ModelName.distinct.count:attribute\u name的解决方案如何返回模型的所有属性？

[11] pry(main)> Needremember.distinct.count(:word)
(1.1ms)  SELECT DISTINCT COUNT(DISTINCT "needremembers"."word") FROM "needremembers"
[12] pry(main)> Needremember.uniq.count(:word)
DEPRECATION WARNING: uniq is deprecated and will be removed from Rails 5.1 (use distinct instead) (called from __pry__ at (pry):12)
   (0.6ms)  SELECT DISTINCT COUNT(DISTINCT "needremembers"."word") FROM "needremembers"