Instance Public methods
unscoped() Link
Returns a scope for the model without the previously set scopes.
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"
Post.where(published: false).unscoped.all # Fires "SELECT * FROM posts"
This method also accepts a block. All queries inside the block will not use the previously set scopes.
Post.unscoped {
Post.limit(10) # Fires "SELECT * FROM posts LIMIT 10"
}
Instance Private methods
default_scope(scope = nil, &block) Link
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 88 def default_scope(scope = nil, &block) # :doc: scope = block if block_given? if scope.is_a?(Relation) || !scope.respond_to?(:call) raise ArgumentError, "Support for calling #default_scope without a block is removed. 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