只在Rails中选择模型的某些孩子

Question

说我有一个模型用户has_many发布子女。

user = User.first 
posts = user.posts 

，但我怎么能削减下来的职位，以满足某些条件：

很显然，我可以用这样的访问的孩子吗？

user = User.first 
posts = user.posts 
recent_posts = posts.where(:created_at => > (Time.now - 1.day)) 

我on Rails的2.3.11

Answer 1

Rails2：

recent_posts = posts.all(:conditions=> ['created_at > ?', (Time.now - 1.day)]) 

Rails3中：

recent_posts = posts.where('created_at > ?', (Time.now - 1.day)) 

Answer 2

试试这个：

class User 
    has_many :posts do 
    def recent duration=1.day 
     all(:conditions => ["created_at >= ? ", duration.ago]) 
    end 
    end 

end 

现在您可以拨打以下电话：

user.posts # all posts for user 
user.posts.recent # posts since last one day 
user.posts.recent(2.days) # posts since last two days 
user.posts.recent(30.minutes) # posts since last 30 minutes