Question

是否有办法执行.includes并指定左外连接。

最初：

@post = Post.includes(:comments).where("comments.spam = ?", false).where(:id => params[:id]).first
@comments = post.comments

欲望是模仿：

@post = Post.find(params[:id])
@comments = post.comments.where(:spam => false)

除了使用包含会以急切的加载方式执行它（如果说我有多个帖子）。

感谢先进的帮助。贾斯汀

Answer 1

我会做以下事情：

class Post < ActiveRecord::Base
  has_many :comments

  has_many :non_spam_comments, :through => :comments, :conditions => {:spam => false} 
  has_many :spam_comments, :through => :comments, :conditions => {:spam => true}
end

然后，您将能够：

@posts = Post.where(:user_id => current_user.id).includes(:non_spam_comments)
@posts.each do |post|
  post.non_spam_comments.each do |comment| 
    // Some comment operation
  end
end

外左连接包括Rails 3

1 个答案: