Returns a scope for the model without the default_scope
.
class Post < ActiveRecord::Base def self.default_scope where published: true end end Post.all # Fires "SELECT * FROM posts WHERE published = true" Post.unscoped.all # Fires "SELECT * FROM posts"
This method also accepts a block. All queries inside the block will not use
the default_scope
:
Post.unscoped { Post.limit(10) # Fires "SELECT * FROM posts LIMIT 10" }
Use this macro in your model to set a default scope for all operations on the model.
class Article < ActiveRecord::Base default_scope { where(published: true) } end Article.all # => SELECT * FROM articles WHERE published = true
The default_scope
is also applied while creating/building a
record. It is not applied while updating a record.
Article.new.published # => true Article.create.published # => true
(You can also pass any object which responds to call
to the
default_scope
macro, and it will be called when building the
default scope.)
If you use multiple default_scope
declarations in your model
then they will be merged together:
class Article < ActiveRecord::Base default_scope { where(published: true) } default_scope { where(rating: 'G') } end Article.all # => SELECT * FROM articles WHERE published = true AND rating = 'G'
This is also the case with inheritance and module includes where the parent
or module defines a default_scope
and the child or including
class defines a second one.
If you need to do more complex things with a default scope, you can alternatively define it as a class method:
class Article < ActiveRecord::Base def self.default_scope # Should return a scope, you can call 'super' here etc. end end
# File activerecord/lib/active_record/scoping/default.rb, line 90 def default_scope(scope = nil) scope = Proc.new if block_given? if scope.is_a?(Relation) || !scope.respond_to?(:call) ActiveSupport::Deprecation.warn( "Calling #default_scope without a block is deprecated. For example instead " "of `default_scope where(color: 'red')`, please use " "`default_scope { where(color: 'red') }`. (Alternatively you can just redefine " "self.default_scope.)" ) end self.default_scopes += [scope] end