在Ruby中，“作用域”是什么意思？

Question

I've come across this code:

def self.search(search)
    if search
      where(['title LIKE ? OR description LIKE ? ', "%#{search}%", "%#{search}%"])  
    else
      scoped
    end
  end

What does the "scoped" statement refer to? It's surprisingly hard to Google.

Answer 1

I think the essence of the above snippet is: "if a search parameter is provided, create an ActiveRecord query that restricts the records returned. Otherwise, return a blank slate query." So "scoped" is a (weirdly named) object that represents a query that can be further refined before being eventually executed.

http://guides.rubyonrails.org/active_record_querying.html