Class AWS::Record::HashModel::Scope
In: lib/aws/record/hash_model/scope.rb
Parent: Record::Scope

The primary interface for finding records with {AWS::Record::HashModel}.

Getting a Scope Object

You should normally never need to construct a Scope object directly. Scope objects are returned from the AWS::Record::HashModel finder methods # (e.g. shard and limit).

  books = Book.limit(100)
  books.class #=> AWS::Record::HashModel::Scope

Scopes are also returned from methods defined with the scope method.

  class Book < AWS::Record::HashModel
     scope :sampling, limit(10)
  end

  Book.sampling #=> returns a scope that limits to 10

Chaining Scopes

Scope objects represent a request, but do not actualy make a request until required. This allows you to chain requests

  # no request made by the following 2 statements
  books = Book.shard('books-1') # what table to search
  books = books.limit(10) # how many records to fetch

  books.each do |book|
    # yields up to 10 books from the table 'books-1'
  end

The following methods returns a scope that can be chained.

  • {shard}
  • {limit}

Terminating Scopes

To terminate a scope you can enumerate it or call first.

  # terminate a scope by enumerating
  Book.limit(10).each {|book| ... }

  # terminate a scope by getting the first record
  Book.shard('books-1').first

[Validate]