向 Rails 中的所有 Active Record 模型添加查找条件 [英] Adding find condition to all Active Record Models in Rails

问题描述

是否有向所有活动记录模型添加查找条件?

Is there anyway to add a find condition to all Active record models?

就是我想要这个查询

ExampleModel.find :all, :conditions=> ["status = ?", "active"]

表现得和

ExampleModel.find :all

在每个模型中

谢谢！！

推荐答案

你可以使用 default_scope:

You could use default_scope:

class ExampleModel < ActiveRecord::Base
  default_scope :conditions => ["status = ?", "active"]
end

如果您想在所有模型中使用它，您可以继承 ActiveRecord::Base 并在所有模型中派生它(可能不适用于单表继承):

If you want to use this in all your models, you can either subclass ActiveRecord::Base and derive from that in all your models (probably doesn't work well with single-table inheritance):

class MyModel < ActiveRecord::Base
  default_scope :conditions => ["status = ?", "active"]
end
class ExampleModel < MyModel
end

...或者您可以在 ActiveRecord::Base 本身上设置 default_scope (如果您决定一个模型不应该具有此默认范围，可能会很烦人):

...or you could set the default_scope on ActiveRecord::Base itself (could be annoying if you decide that one model should not have this default scope):

class ActiveRecord::Base
  default_scope :conditions => ["status = ?", "active"]
end
class ExampleModel < ActiveRecord::Base
end

正如 klochner 在评论中提到的，您可能还需要考虑将 named_scope 添加到 ActiveRecord::Base，命名为 active，例如:

As mentioned by klochner in a comment, you may also want to consider adding a named_scope to ActiveRecord::Base, named active, for example:

class ActiveRecord::Base
  named_scope :active, :conditions => ["status = ?", "active"]
end
class ExampleModel < ActiveRecord::Base
end
ExampleModel.active  # Return all active items.

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