Sql Rails邮件日期排序问题
我在使用ActiveRecord按日期排序帖子时遇到问题。。。这不是我所期望的Sql Rails邮件日期排序问题,sql,ruby-on-rails,sorting,activerecord,Sql,Ruby On Rails,Sorting,Activerecord,我在使用ActiveRecord按日期排序帖子时遇到问题。。。这不是我所期望的 1.9.3p194 :019 > Post.all(:select => [:id, :updated_at], :order => "updated_at DESC") Post Load (0.7ms) SELECT id, updated_at FROM "posts" ORDER BY published_at DESC, updated_at DESC +----+---------
1.9.3p194 :019 > Post.all(:select => [:id, :updated_at], :order => "updated_at DESC")
Post Load (0.7ms) SELECT id, updated_at FROM "posts" ORDER BY published_at DESC, updated_at DESC
+----+---------------------------+
| id | updated_at |
+----+---------------------------+
| 22 | 2012-08-16 18:59:28 -0600 |
| 9 | 2012-08-16 18:58:16 -0600 |
| 11 | 2012-08-15 20:18:53 -0600 |
| 1 | 2012-08-15 20:18:52 -0600 |
| 12 | 2012-08-15 20:18:53 -0600 |
| 6 | 2012-08-15 20:18:52 -0600 |
| 13 | 2012-08-15 20:18:53 -0600 |
| 2 | 2012-08-15 20:18:52 -0600 |
| 15 | 2012-08-15 20:18:53 -0600 |
| 5 | 2012-08-16 21:49:14 -0600 |
| 17 | 2012-08-15 20:18:53 -0600 |
| 4 | 2012-08-15 20:18:52 -0600 |
| 20 | 2012-08-15 20:18:53 -0600 |
| 7 | 2012-08-15 20:18:52 -0600 |
| 21 | 2012-08-15 20:18:53 -0600 |
| 14 | 2012-08-15 20:18:53 -0600 |
| 10 | 2012-08-15 20:18:53 -0600 |
| 8 | 2012-08-15 20:18:53 -0600 |
| 19 | 2012-08-15 20:18:53 -0600 |
| 18 | 2012-08-15 20:18:53 -0600 |
| 16 | 2012-08-15 20:18:53 -0600 |
| 3 | 2012-08-15 20:18:52 -0600 |
+----+---------------------------+
请注意,post#5在8月16日进行了更新,但它不会出现在顶部!请注意,Rails似乎对其进行了正确排序
1.9.3p194 :020 > Post.all(:select => [:id, :updated_at], :order => "updated_at DESC").sort_by &:updated_at
Post Load (0.6ms) SELECT id, updated_at FROM "posts" ORDER BY published_at DESC, updated_at DESC
+----+---------------------------+
| id | updated_at |
+----+---------------------------+
| 1 | 2012-08-15 20:18:52 -0600 |
| 2 | 2012-08-15 20:18:52 -0600 |
| 3 | 2012-08-15 20:18:52 -0600 |
| 4 | 2012-08-15 20:18:52 -0600 |
| 6 | 2012-08-15 20:18:52 -0600 |
| 7 | 2012-08-15 20:18:52 -0600 |
| 8 | 2012-08-15 20:18:53 -0600 |
| 10 | 2012-08-15 20:18:53 -0600 |
| 11 | 2012-08-15 20:18:53 -0600 |
| 12 | 2012-08-15 20:18:53 -0600 |
| 13 | 2012-08-15 20:18:53 -0600 |
| 14 | 2012-08-15 20:18:53 -0600 |
| 15 | 2012-08-15 20:18:53 -0600 |
| 16 | 2012-08-15 20:18:53 -0600 |
| 17 | 2012-08-15 20:18:53 -0600 |
| 18 | 2012-08-15 20:18:53 -0600 |
| 19 | 2012-08-15 20:18:53 -0600 |
| 20 | 2012-08-15 20:18:53 -0600 |
| 21 | 2012-08-15 20:18:53 -0600 |
| 9 | 2012-08-16 18:58:16 -0600 |
| 22 | 2012-08-16 18:59:28 -0600 |
| 5 | 2012-08-16 21:49:14 -0600 |
+----+---------------------------+
我相信这很简单。。。如果您能提供任何帮助,我们将不胜感激
我试过这些都没有用:
Post.all(:order => "updated_at DESC")
Post.all(:order => "updated_at DESC").limit(1)
我想我已经弄明白了。。。。我在“created_at”上有一个默认的作用域,我认为它把我搞砸了。好吧,SQL肯定是不正确的
SELECT id, updated_at FROM "posts" ORDER BY published_at DESC, updated_at DESC
应该是
SELECT id, updated_at FROM "posts" ORDER BY updated_at DESC
编辑:
是的,默认范围意味着它将按发布时间和更新时间排序。如果要保留模型中的默认范围,但不使用此查询的范围,可以使用:
Post.unscoped.all(:select => [:id, :updated_at], :order => "updated_at DESC")
你是如何得到这些漂亮的打印表格的?Hirb-控制台中输出结果的宝石。