Tag: 数量

rails COUNT SELECT DISTINCT

我正在记录用户观看一系列video的次数。 现在，我正在尝试制作每天观看任何video的用户数量的图表。 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 这会为每天观看的所有video产生正确的结果，但正如我所说，我只想向每个用户展示一次。 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 != […]