Question

我有一个Rails 3.2应用程序，其工作范围基于相关模型中的字段：

self.searchController.hidesNavigationBarDuringPresentation = NO;
self.searchController.searchBar.searchBarStyle = UISearchBarStyleMinimal;

// Include the search bar within the navigation bar.
self.navigationItem.titleView = self.searchController.searchBar;

self.definesPresentationContext = YES;

我希望结果按scope :maintenance, -> { joins(:costcat).where(costcats: { maintenance: true }) }排序。

我试过这些：

costcats.position

感谢您的帮助！

UPDATE1

根据建议的答案，我得到以下SQL：

scope :maintenance, -> { joins(:costcat).where(costcats: { maintenance: true }).order(costcats.position ASC) }
scope :maintenance, -> { joins(:costcat).where(costcats: { maintenance: true }) }, :order => "costcats.position ASC"

如果SELECT "costestimates".* FROM "costestimates" INNER JOIN "costcats" ON "costcats"."id" = "costestimates"."costcat_id" WHERE "costestimates"."costproject_id" = 1 AND "costcats"."maintenance" = 't' ORDER BY id ASC, position ASC不在ORDER

中，它会起作用

UDDATE2

我的不好，我不得不删除id ASC

中的默认范围顺序

Answer 1

scope :maintenance, 
      ->{ joins(:costcat).where(costcats: { maintenance: true }).order("costcats.position")}

Answer 2

我喜欢使用#merge因为它使查询看起来更干净

scope :maintenance, ->{ joins(:costcat)
                         .merge(
                           Costcat.where(maintenance: true).order(:position)
                         )
                       }

PS：多行仅用于提高可读性

Rails将命令添加到范围

2 个答案: