Class AWS::Record::Model::Scope
In: lib/aws/record/model/scope.rb
Parent: Record::Scope

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

Getting a Scope Object

You should normally never need to construct a Scope object directly. Scope objects are returned from the AWS::Record::Model finder methods (e.g. shard, where, order, limit, etc).

  books = Book.where(:author => 'John Doe')
  books.class #=> AWS::Record::Scope, not Array

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

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.where(:author => 'John Doe')
  books = books.limit(10)

  books.each do |book|
    # yields up to 10 books
  end

Each of the following methods returns a scope that can be chained.

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 value
  Book.where('author' => 'John Doe').first

Methods

new   new   order   where  

Public Class methods

Public Instance methods

Specifies how to sort records returned.

  # enumerate books, starting with the most recently published ones
  Book.order(:published_at, :desc).each do |book|
    # ...
  end

Only one order may be applied. If order is specified more than once the last one in the chain takes precedence:

  # books returned by this scope will be ordered by :published_at
  # and not :author.
  Book.where(:read => false).order(:author).order(:published_at)

@param [String,Symbol] attribute_name The attribute to sort by. @param [:asc, :desc] order (:asc) The direct to sort.

Applies conditions to the scope that limit which records are returned. Only those matching all given conditions will be returned.

@overload where(conditions_hash)

  Specify a hash of conditions to query with.  Multiple conditions
  are joined together with AND.

    Book.where(:author => 'John Doe', :softcover => true)
    # where `author` = `John Doe` AND `softcover` = `1`

  @param [Hash] conditions

@overload where(conditions_string, *values)

  A sql-like query fragment with optional placeholders and values.
  Placeholders are replaced with properly quoted values.

    Book.where('author = ?', 'John Doe')

  @param [String] conditions_string A sql-like where string with
    question mark placeholders.  For each placeholder there should
    be a value that will be quoted into that position.
  @param [String] *values A value that should be quoted into the
    corresponding (by position) placeholder.

@return [Scope] Returns a new scope with the passed conditions applied.

[Validate]