从ActiveRecord范围中删除订单

我正在使用Rails ransack（https://github.com/ernie/ransack）来允许用户过滤和排序一些记录。我使用传统方法获得了经过过滤和排序的记录。

 @invoices = Invoice.search(params[:q]).result

现在我想获得一些摘要信息，所以我有

 @invoices = Invoice.search(params[:q]).result
 @summary = @invoices.select("sum(balance) as balance_total").first

用户指定要排序的字段时除外。我收到SQL错误：

 Column "project_name" is invalid in the ORDER BY clause because 
 it is not contained in either an aggregate function or the GROUP BY clause

我可以从示波器中删除排序吗？怎么样？

谢谢

您可以使用空字符串调用reorder方法。例如：

Article.order('headline asc').to_sql
# "SELECT `articles`.* FROM `articles`  ORDER BY headline asc"
Article.order('headline asc').reorder('').to_sql
# "SELECT `articles`.* FROM `articles` "

您还可以unscoped在Rails 3中使用class方法：

class Post < ActiveRecord::Base
  default_scope :published => true
end

posts = Post.all #=> SELECT * FROM posts WHERE published = true

posts = Post.unscoped do
  Post.all #=> SELECT * FROM posts
end

在Rails 2中被称为with_exclusive_scope。

参见https://github.com/rails/rails/commit/bd1666ad1de88598ed6f04ceffb8488a77be4385