Tag: 不同

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 != […]

Uniq的ruby数组无法正常工作

我有一个我的对象Country的数组，它具有“代码”和“名称”的属性 该arrays可能不止一次有一个国家，所以我想区分数组。 这是我的国家级 class Country include Mongoid::Fields::Serializable attr_accessor :name, :code FILTERS = [“Afghanistan”,”Brunei”,”Iran”, “Kuwait”, “Libya”, “Saudi Arabia”, “Sudan”, “Yemen”, “Britain (UK)”, “Antarctica”, “Bonaire Sint Eustatius & Saba”, “British Indian Ocean Territory”, “Cocos (Keeling) Islands”, “St Barthelemy”, “St Martin (French part)”, “Svalbard & Jan Mayen”,”Vatican City”] EXTRAS = { ‘eng’ => ‘England’, ‘wal’ => ‘Wales’, ‘sco’ […]