Class: ActiveRecord::AssociationRelation

Relationships & Source Files
Super Chains via Extension / Inclusion / Inheritance
Class Chain: self, `Relation`
Instance Chain: self, `Relation`, `FinderMethods`, `Calculations`, `SpawnMethods`, `QueryMethods`, `Batches`, `Explain`, `::Enumerable`
Inherits:	ActiveRecord::Relation `::Object` ActiveRecord::Relation ActiveRecord::AssociationRelation
Defined in:	activerecord/lib/active_record/association_relation.rb

Constant Summary

Class Method Summary

.new(klass, association) ⇒ AssociationRelation constructor

`Relation` - Inherited

.new

Instance Attribute Summary

`Relation` - Inherited

#any?	Returns true if there are any records.
#blank?	Returns true if relation is blank.
#eager_loading?	Returns true if relation needs eager loading.
#empty?	Returns true if there are no records.
#klass,
#loaded?	Alias for Relation#loaded.
#many?	Returns true if there is more than one record.
#model	Alias for Relation#klass.
#none?	Returns true if there are no records.
#one?	Returns true if there is exactly one record.
#predicate_builder, #table

`::Enumerable` - Included

#many?

Returns true if the enumerable has more than 1 element.

Instance Method Summary

#==(other)
#build(*args, &block) (also: #new)
#create(*args, &block)
#create!(*args, &block)
#new(*args, &block)

Alias for #build.
#proxy_association

`Relation` - Inherited

#==	Compares two relations for equality.
#build	Alias for Relation#new.
#cache_key	Returns a cache key that can be used to identify the records fetched by this query.
#create	Tries to create a new record with the same scoped attributes defined in the relation.
#create!	Similar to #create, but calls create! on the base class.
#delete_all	Deletes the records without instantiating the records first, and hence not calling the #destroy method nor invoking callbacks.
#destroy_all	Destroys the records by instantiating each record and calling its #destroy method.
#encode_with	Serializes the relation objects `::Array`.
#explain	Runs EXPLAIN on the query or queries triggered by this relation and returns the result as a string.
#find_or_create_by	Finds the first record with the given attributes, or creates a record with the attributes if one is not found:
#find_or_create_by!	Like `#find_or_create_by`, but calls create! so an exception is raised if the created record is invalid.
#find_or_initialize_by	Like `#find_or_create_by`, but calls `new` instead of create.
#initialize_copy, #inspect,
#joined_includes_values	Joins that are also marked for preloading.
#load	Causes the records to be loaded from the database if they have not been loaded already.
#loaded, #locked?,
#new	Initializes new record from relation while maintaining the current scope.
#pretty_print,
#reload	Forces reloading of relation.
#reset, #scope_for_create,
#scoping	Scope all queries to the current scope.
#size	Returns size of the records.
#to_a	Alias for Relation#to_ary.
#to_ary	Converts relation objects to `::Array`.
#to_sql	Returns sql statement for the relation.
#update_all	Updates all records in the current relation with details given.
#values,
#where_values_hash	Returns a hash of where conditions.

`FinderMethods` - Included

#exists?	Returns true if a record exists in the table that matches the `id` or conditions given, or false otherwise.
#fifth	Find the fifth record.
#fifth!	Same as `#fifth` but raises `RecordNotFound` if no record is found.
#find	Find by id - This can either be a specific id (1), a list of ids (1, 5, 6), or an array of ids ([5, 6, 10]).
#find_by	Finds the first record matching the specified conditions.
#find_by!	Like `#find_by`, except that if no record is found, raises an `RecordNotFound` error.
#first	Find the first record (or first N records if a parameter is supplied).
#first!	Same as `#first` but raises `RecordNotFound` if no record is found.
#forty_two	Find the forty-second record.
#forty_two!	Same as `#forty_two` but raises `RecordNotFound` if no record is found.
#fourth	Find the fourth record.
#fourth!	Same as `#fourth` but raises `RecordNotFound` if no record is found.
#last	Find the last record (or last N records if a parameter is supplied).
#last!	Same as `#last` but raises `RecordNotFound` if no record is found.
#second	Find the second record.
#second!	Same as `#second` but raises `RecordNotFound` if no record is found.
#second_to_last	Find the second-to-last record.
#second_to_last!	Same as `#second_to_last` but raises `RecordNotFound` if no record is found.
#take	Gives a record (or N records if a parameter is supplied) without any implied order.
#take!	Same as `#take` but raises `RecordNotFound` if no record is found.
#third	Find the third record.
#third!	Same as `#third` but raises `RecordNotFound` if no record is found.
#third_to_last	Find the third-to-last record.
#third_to_last!	Same as `#third_to_last` but raises `RecordNotFound` if no record is found.

`Calculations` - Included

#average	Calculates the average value on a given column.
#calculate	This calculates aggregate values in the given column.
#count	Count the records.
#ids	Pluck all the ID’s for the relation using the table’s primary key.
#maximum	Calculates the maximum value on a given column.
#minimum	Calculates the minimum value on a given column.
#pluck	Use `#pluck` as a shortcut to select one or more attributes without loading a bunch of records just to grab the attributes you want.
#sum	Calculates the sum of values on a given column.

`SpawnMethods` - Included

#except	Removes from the query the condition(s) specified in `skips`.
#merge	Merges in the conditions from `other`, if `other` is an `Relation`.
#only	Removes any condition from the query other than the one(s) specified in `onlies`.

`QueryMethods` - Included

#create_with	Sets attributes to be used when creating new records from a relation object.
#distinct	Specifies whether the records should be unique or not.
#eager_load	Forces eager loading by performing a LEFT OUTER JOIN on `args`:
#extending	Used to extend a scope with additional methods, either through a module or through a block provided.
#extensions,
#from	Specifies table from which the records will be fetched.
#group	Allows to specify a group attribute:
#having	Allows to specify a HAVING clause.
#includes	Specify relationships to be included in the result set.
#joins	Performs a joins on `args`.
#left_joins	Alias for QueryMethods#left_outer_joins.
#left_outer_joins	Performs a left outer joins on `args`:
#limit	Specifies a limit for the number of records to retrieve.
#lock	Specifies locking settings (default to `true`).
#none	Returns a chainable relation with zero records.
#offset	Specifies the number of rows to skip before returning rows.
#or	Returns a new relation, which is the logical union of this relation and the one passed as an argument.
#order	Allows to specify an order attribute:
#preload	Allows preloading of `args`, in the same way that `#includes` does:
#readonly	Sets readonly attributes for the returned relation.
#references	Use to indicate that the given `table_names` are referenced by an SQL string, and should therefore be JOINed in any query rather than loaded separately.
#reorder	Replaces any existing order defined on the relation with the specified order.
#reverse_order	Reverse the existing order clause on the relation.
#rewhere	Allows you to change a previously set where condition for a given attribute, instead of appending to that condition.
#select	Works in two unique ways.
#unscope	Removes an unwanted relation that is already defined on a chain of relations.
#where	Returns a new relation, which is the result of filtering the current relation according to the conditions in the arguments.

`Batches` - Included

#find_each	Looping through a collection of records from the database (using the Scoping::Named::ClassMethods#all method, for example) is very inefficient since it will try to instantiate all the objects at once.
#find_in_batches	Yields each batch of records that was found by the find options as an array.
#in_batches	Yields `Relation` objects to work with a batch of records.

`::Enumerable` - Included

#exclude?	The negative of the `Enumerable#include?`.
#index_by	Convert an enumerable to a hash.
#pluck	Convert an enumerable to an array based on the given key.
#sum	Calculates a sum from the elements.
#without	Returns a copy of the enumerable without the specified elements.

Constructor Details

.new(klass, association) ⇒ `AssociationRelation`

[ GitHub ]

# File 'activerecord/lib/active_record/association_relation.rb', line 5


def initialize(klass, association)
  super(klass)
  @association = association
end

Instance Method Details

#==(other)

[ GitHub ]

# File 'activerecord/lib/active_record/association_relation.rb', line 14


def ==(other)
  other == records
end

#build(*args, &block) Also known as: #new

[ GitHub ]

# File 'activerecord/lib/active_record/association_relation.rb', line 18


def build(*args, &block)
  scoping { @association.build(*args, &block) }
end

#create(*args, &block)

[ GitHub ]

# File 'activerecord/lib/active_record/association_relation.rb', line 23


def create(*args, &block)
  scoping { @association.create(*args, &block) }
end

#create!(*args, &block)

[ GitHub ]

# File 'activerecord/lib/active_record/association_relation.rb', line 27


def create!(*args, &block)
  scoping { @association.create!(*args, &block) }
end

#new(*args, &block)

Alias for #build.

[ GitHub ]

# File 'activerecord/lib/active_record/association_relation.rb', line 21


alias new build

#proxy_association

[ GitHub ]

# File 'activerecord/lib/active_record/association_relation.rb', line 10


def proxy_association
  @association
end

Class: ActiveRecord::AssociationRelation

Constant Summary

Batches - Included

QueryMethods - Included

FinderMethods - Included

Relation - Inherited

Class Method Summary

Relation - Inherited

Instance Attribute Summary

Relation - Inherited

::Enumerable - Included

Instance Method Summary

Relation - Inherited

FinderMethods - Included

Calculations - Included

SpawnMethods - Included

QueryMethods - Included

Batches - Included

::Enumerable - Included

Constructor Details

.new(klass, association) ⇒ AssociationRelation

Instance Method Details

#==(other)

#build(*args, &block) Also known as: #new

#create(*args, &block)

#create!(*args, &block)

#new(*args, &block)

#proxy_association

`Batches` - Included

`QueryMethods` - Included

`FinderMethods` - Included

`Relation` - Inherited

`Relation` - Inherited

`Relation` - Inherited

`::Enumerable` - Included

`Relation` - Inherited

`FinderMethods` - Included

`Calculations` - Included

`SpawnMethods` - Included

`QueryMethods` - Included

`Batches` - Included

`::Enumerable` - Included

.new(klass, association) ⇒ `AssociationRelation`