Module: ActiveRecord::FinderMethods
Relationships & Source Files | |
Extension / Inclusion / Inheritance Descendants | |
Included In:
| |
Defined in: | activerecord/lib/active_record/relation/finder_methods.rb |
Constant Summary
-
ONE_AS_ONE =
# File 'activerecord/lib/active_record/relation/finder_methods.rb', line 7"1 AS one"
Instance Method Summary
-
#exists?(conditions = :none) ⇒ Boolean
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(*args)
Find by id - This can either be a specific id (ID), a list of ids (ID, ID, ID), or an array of ids ([ID, ID, ID]).
-
#find_by(arg, *args)
Finds the first record matching the specified conditions.
-
#find_by!(arg, *args)
Like #find_by, except that if no record is found, raises an
RecordNotFound
error. -
#find_sole_by(arg, *args)
Finds the sole matching record.
-
#first(limit = nil)
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. -
#include?(record) ⇒ Boolean
(also: #member?)
Returns true if the relation contains the given record or false otherwise.
-
#last(limit = nil)
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. -
#member?(record)
Alias for #include?.
-
#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. -
#sole
Finds the sole matching record.
-
#take(limit = nil)
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. - #_order_columns private
- #apply_join_dependency(eager_loading: group_values.empty?) private
- #construct_relation_for_exists(conditions) private
- #find_last(limit) private
- #find_nth(index) private
- #find_nth_from_last(index) private
- #find_nth_with_limit(index, limit) private
- #find_one(id) private
- #find_some(ids) private
- #find_some_ordered(ids) private
- #find_take private
- #find_take_with_limit(limit) private
- #find_with_ids(*ids) private
- #ordered_relation private
- #using_limitable_reflections?(reflections) ⇒ Boolean private
-
#raise_record_not_found_exception!(ids = nil, result_size = nil, expected_size = nil, key = primary_key, not_found_ids = nil)
Internal use only
This method is called whenever no records are found with either a single id or multiple ids and raises an
RecordNotFound
exception.
Instance Method Details
#_order_columns (private)
[ GitHub ]# File 'activerecord/lib/active_record/relation/finder_methods.rb', line 648
def _order_columns oc = [] oc << model.implicit_order_column if model.implicit_order_column oc << model.query_constraints_list if model.query_constraints_list if model.primary_key && model.query_constraints_list.nil? oc << model.primary_key end oc.flatten.uniq.compact end
#apply_join_dependency(eager_loading: group_values.empty?) (private)
[ GitHub ]# File 'activerecord/lib/active_record/relation/finder_methods.rb', line 457
def apply_join_dependency(eager_loading: group_values.empty?) join_dependency = construct_join_dependency( eager_load_values | includes_values, Arel::Nodes::OuterJoin ) relation = except(:includes, :eager_load, :preload).joins!(join_dependency) if eager_loading && has_limit_or_offset? && !( using_limitable_reflections?(join_dependency.reflections) && using_limitable_reflections?( construct_join_dependency( select_association_list(joins_values).concat( select_association_list(left_outer_joins_values) ), nil ).reflections ) ) relation = skip_query_cache_if_necessary do model.with_connection do |c| c.distinct_relation_for_primary_key(relation) end end end if block_given? yield relation, join_dependency else relation end end
#construct_relation_for_exists(conditions) (private)
[ GitHub ]# File 'activerecord/lib/active_record/relation/finder_methods.rb', line 438
def construct_relation_for_exists(conditions) conditions = sanitize_forbidden_attributes(conditions) if distinct_value && offset_value relation = except(:order).limit!(1) else relation = except(:select, :distinct, :order)._select!(ONE_AS_ONE).limit!(1) end case conditions when Array, Hash relation.where!(conditions) unless conditions.empty? else relation.where!(primary_key => conditions) unless conditions == :none end relation end
#exists?(conditions = :none) ⇒ Boolean
Returns true if a record exists in the table that matches the id
or conditions given, or false otherwise. The argument can take six forms:
-
::Integer
- Finds the record with this primary key. -
::String
- Finds the record with a primary key corresponding to this string (such as'5'
). -
::Array
- Finds the record that matches thesewhere
-style conditions (such as['name LIKE ?', "%#{query}%"]
). -
::Hash
- Finds the record that matches thesewhere
-style conditions (such as{name: 'David'}
). -
false
- Returns alwaysfalse
. -
No args - Returns
false
if the relation is empty,true
otherwise.
For more information about specifying conditions as a hash or array, see the Conditions section in the introduction to Base
.
Note: You can’t pass in a condition as a string (like name = 'Jamie'
), since it would be sanitized and then queried against the primary key column, like id = 'name = \'Jamie\''
.
Person.exists?(5)
Person.exists?('5')
Person.exists?(['name LIKE ?', "%#{query}%"])
Person.exists?(id: [1, 4, 8])
Person.exists?(name: 'David')
Person.exists?(false)
Person.exists?
Person.where(name: 'Spartacus', rating: 4).exists?
# File 'activerecord/lib/active_record/relation/finder_methods.rb', line 357
def exists?(conditions = :none) return false if @none if Base === conditions raise ArgumentError, <<-MSG.squish You are passing an instance of ActiveRecord::Base to `exists?`. Please pass the id of the object by calling `.id`. MSG end return false if !conditions || limit_value == 0 if eager_loading? relation = apply_join_dependency(eager_loading: false) return relation.exists?(conditions) end relation = construct_relation_for_exists(conditions) return false if relation.where_clause.contradiction? skip_query_cache_if_necessary do with_connection do |c| c.select_rows(relation.arel, "#{model.name} Exists?").size == 1 end end end
#fifth
Find the fifth record. If no order is defined it will order by primary key.
Person.fifth # returns the fifth object fetched by SELECT * FROM people
Person.offset(3).fifth # returns the fifth object from OFFSET 3 (which is OFFSET 7)
Person.where(["user_name = :u", { u: user_name }]).fifth
# File 'activerecord/lib/active_record/relation/finder_methods.rb', line 271
def fifth find_nth 4 end
#fifth!
Same as #fifth but raises RecordNotFound
if no record is found.
# File 'activerecord/lib/active_record/relation/finder_methods.rb', line 277
def fifth! fifth || raise_record_not_found_exception! end
#find(*args)
Find by id - This can either be a specific id (ID), a list of ids (ID, ID, ID), or an array of ids ([ID, ID, ID]). ID
refers to an “identifier”. For models with a single-column primary key, ID
will be a single value, and for models with a composite primary key, it will be an array of values. If one or more records cannot be found for the requested ids, then RecordNotFound
will be raised. If the primary key is an integer, find by id coerces its arguments by using to_i
.
Person.find(1) # returns the object for ID = 1
Person.find("1") # returns the object for ID = 1
Person.find("31-sarah") # returns the object for ID = 31
Person.find(1, 2, 6) # returns an array for objects with IDs in (1, 2, 6)
Person.find([7, 17]) # returns an array for objects with IDs in (7, 17), or with composite primary key [7, 17]
Person.find([1]) # returns an array for the object with ID = 1
Person.where("administrator = 1").order("created_on DESC").find(1)
Find a record for a composite primary key model
TravelRoute.primary_key = [:origin, :destination]
TravelRoute.find(["Ottawa", "London"])
#=> #<TravelRoute origin: "Ottawa", destination: "London">
TravelRoute.find([["Paris", "Montreal"]])
#=> [#<TravelRoute origin: "Paris", destination: "Montreal">]
TravelRoute.find(["New York", "Las Vegas"], ["New York", "Portland"])
#=> [
#<TravelRoute origin: "New York", destination: "Las Vegas">,
#<TravelRoute origin: "New York", destination: "Portland">
]
TravelRoute.find([["Berlin", "London"], ["Barcelona", "Lisbon"]])
#=> [
#<TravelRoute origin: "Berlin", destination: "London">,
#<TravelRoute origin: "Barcelona", destination: "Lisbon">
]
NOTE: The returned records are in the same order as the ids you provide. If you want the results to be sorted by database, you can use QueryMethods#where method and provide an explicit QueryMethods#order option. But QueryMethods#where method doesn’t raise RecordNotFound
.
Find with lock
Example for find with a lock: Imagine two concurrent transactions: each will read person.visits == 2
, add 1 to it, and save, resulting in two saves of person.visits = 3
. By locking the row, the second transaction has to wait until the first is finished; we get the expected person.visits == 4
.
Person.transaction do
person = Person.lock(true).find(1)
person.visits += 1
person.save!
end
Variations of #find
Person.where(name: 'Spartacus', rating: 4)
# returns a chainable list (which can be empty).
Person.find_by(name: 'Spartacus', rating: 4)
# returns the first item or nil.
Person.find_or_initialize_by(name: 'Spartacus', rating: 4)
# returns the first item or returns a new instance (requires you call .save to persist against the database).
Person.find_or_create_by(name: 'Spartacus', rating: 4)
# returns the first item or creates it and returns it.
Alternatives for #find
Person.where(name: 'Spartacus', rating: 4).exists?(conditions = :none)
# returns a boolean indicating if any record with the given conditions exist.
Person.where(name: 'Spartacus', rating: 4).select("field1, field2, field3")
# returns a chainable list of instances with only the mentioned fields.
Person.where(name: 'Spartacus', rating: 4).ids
# returns an Array of ids.
Person.where(name: 'Spartacus', rating: 4).pluck(:field1, :field2)
# returns an Array of the required fields.
Edge Cases
Person.find(37) # raises ActiveRecord::RecordNotFound exception if the record with the given ID does not exist.
Person.find([37]) # raises ActiveRecord::RecordNotFound exception if the record with the given ID in the input array does not exist.
Person.find(nil) # raises ActiveRecord::RecordNotFound exception if the argument is nil.
Person.find([]) # returns an empty array if the argument is an empty array.
Person.find # raises ActiveRecord::RecordNotFound exception if the argument is not provided.
# File 'activerecord/lib/active_record/relation/finder_methods.rb', line 98
def find(*args) return super if block_given? find_with_ids(*args) end
#find_by(arg, *args)
Finds the first record matching the specified conditions. There is no implied ordering so if order matters, you should specify it yourself.
If no record is found, returns nil
.
Post.find_by name: 'Spartacus', rating: 4
Post.find_by "published_at < ?", 2.weeks.ago
# File 'activerecord/lib/active_record/relation/finder_methods.rb', line 111
def find_by(arg, *args) where(arg, *args).take end
#find_by!(arg, *args)
Like #find_by, except that if no record is found, raises an RecordNotFound
error.
# File 'activerecord/lib/active_record/relation/finder_methods.rb', line 117
def find_by!(arg, *args) where(arg, *args).take! end
#find_last(limit) (private)
[ GitHub ]#find_nth(index) (private)
[ GitHub ]# File 'activerecord/lib/active_record/relation/finder_methods.rb', line 598
def find_nth(index) @offsets ||= {} @offsets[index] ||= find_nth_with_limit(index, 1).first end
#find_nth_from_last(index) (private)
[ GitHub ]# File 'activerecord/lib/active_record/relation/finder_methods.rb', line 622
def find_nth_from_last(index) if loaded? records[-index] else relation = ordered_relation if relation.order_values.empty? || relation.has_limit_or_offset? relation.records[-index] else relation.reverse_order.offset(index - 1).first end end end
#find_nth_with_limit(index, limit) (private)
[ GitHub ]# File 'activerecord/lib/active_record/relation/finder_methods.rb', line 603
def find_nth_with_limit(index, limit) if loaded? records[index, limit] || [] else relation = ordered_relation if limit_value limit = [limit_value - index, limit].min end if limit > 0 relation = relation.offset((offset_value || 0) + index) unless index.zero? relation.limit(limit).to_a else [] end end end
#find_one(id) (private)
[ GitHub ]# File 'activerecord/lib/active_record/relation/finder_methods.rb', line 520
def find_one(id) if ActiveRecord::Base === id raise ArgumentError, <<-MSG.squish You are passing an instance of ActiveRecord::Base to `find`. Please pass the id of the object by calling `.id`. MSG end relation = if model.composite_primary_key? where(primary_key.zip(id).to_h) else where(primary_key => id) end record = relation.take raise_record_not_found_exception!(id, 0, 1) unless record record end
#find_sole_by(arg, *args)
Finds the sole matching record. Raises RecordNotFound
if no record is found. Raises SoleRecordExceeded
if more than one record is found.
Product.find_sole_by(["price = %?", price])
# File 'activerecord/lib/active_record/relation/finder_methods.rb', line 160
def find_sole_by(arg, *args) where(arg, *args).sole end
#find_some(ids) (private)
[ GitHub ]# File 'activerecord/lib/active_record/relation/finder_methods.rb', line 541
def find_some(ids) return find_some_ordered(ids) unless order_values.present? relation = where(primary_key => ids) relation = relation.select(table[primary_key]) unless select_values.empty? result = relation.to_a expected_size = if limit_value && ids.size > limit_value limit_value else ids.size end # 11 ids with limit 3, offset 9 should give 2 results. if offset_value && (ids.size - offset_value < expected_size) expected_size = ids.size - offset_value end if result.size == expected_size result else raise_record_not_found_exception!(ids, result.size, expected_size) end end
#find_some_ordered(ids) (private)
[ GitHub ]# File 'activerecord/lib/active_record/relation/finder_methods.rb', line 567
def find_some_ordered(ids) ids = ids.slice(offset_value || 0, limit_value || ids.size) || [] relation = except(:limit, :offset) relation = relation.where(primary_key => ids) relation = relation.select(table[primary_key]) unless select_values.empty? result = relation.records if result.size == ids.size result.in_order_of(:id, ids.map { |id| model.type_for_attribute(primary_key).cast(id) }) else raise_record_not_found_exception!(ids, result.size, ids.size) end end
#find_take (private)
[ GitHub ]#find_take_with_limit(limit) (private)
[ GitHub ]# File 'activerecord/lib/active_record/relation/finder_methods.rb', line 590
def find_take_with_limit(limit) if loaded? records.take(limit) else limit(limit).to_a end end
#find_with_ids(*ids) (private)
# File 'activerecord/lib/active_record/relation/finder_methods.rb', line 491
def find_with_ids(*ids) raise UnknownPrimaryKey.new(model) if primary_key.nil? expects_array = if model.composite_primary_key? ids.first.first.is_a?(Array) else ids.first.is_a?(Array) end return [] if expects_array && ids.first.empty? ids = ids.first if expects_array ids = ids.compact.uniq model_name = model.name case ids.size when 0 = "Couldn't find #{model_name} without an ID" raise RecordNotFound.new(, model_name, primary_key) when 1 result = find_one(ids.first) expects_array ? [ result ] : result else find_some(ids) end end
#first(limit = nil)
Find the first record (or first N records if a parameter is supplied). If no order is defined it will order by primary key.
Person.first # returns the first object fetched by SELECT * FROM people ORDER BY people.id LIMIT 1
Person.where(["user_name = ?", user_name]).first
Person.where(["user_name = :u", { u: user_name }]).first
Person.order("created_on DESC").offset(5).first
Person.first(3) # returns the first three objects fetched by SELECT * FROM people ORDER BY people.id LIMIT 3
# File 'activerecord/lib/active_record/relation/finder_methods.rb', line 173
def first(limit = nil) if limit find_nth_with_limit(0, limit) else find_nth 0 end end
#first!
Same as #first but raises RecordNotFound
if no record is found. Note that #first!
accepts no arguments.
# File 'activerecord/lib/active_record/relation/finder_methods.rb', line 183
def first! first || raise_record_not_found_exception! end
#forty_two
Find the forty-second record. Also known as accessing “the reddit”. If no order is defined it will order by primary key.
Person.forty_two # returns the forty-second object fetched by SELECT * FROM people
Person.offset(3).forty_two # returns the forty-second object from OFFSET 3 (which is OFFSET 44)
Person.where(["user_name = :u", { u: user_name }]).forty_two
# File 'activerecord/lib/active_record/relation/finder_methods.rb', line 287
def forty_two find_nth 41 end
#forty_two!
Same as #forty_two but raises RecordNotFound
if no record is found.
# File 'activerecord/lib/active_record/relation/finder_methods.rb', line 293
def forty_two! forty_two || raise_record_not_found_exception! end
#fourth
Find the fourth record. If no order is defined it will order by primary key.
Person.fourth # returns the fourth object fetched by SELECT * FROM people
Person.offset(3).fourth # returns the fourth object from OFFSET 3 (which is OFFSET 6)
Person.where(["user_name = :u", { u: user_name }]).fourth
# File 'activerecord/lib/active_record/relation/finder_methods.rb', line 255
def fourth find_nth 3 end
#fourth!
Same as #fourth but raises RecordNotFound
if no record is found.
# File 'activerecord/lib/active_record/relation/finder_methods.rb', line 261
def fourth! fourth || raise_record_not_found_exception! end
#include?(record) ⇒ Boolean
Also known as: #member?
Returns true if the relation contains the given record or false otherwise.
No query is performed if the relation is loaded; the given record is compared to the records in memory. If the relation is unloaded, an efficient existence query is performed, as in #exists?.
# File 'activerecord/lib/active_record/relation/finder_methods.rb', line 389
def include?(record) # The existing implementation relies on receiving an Active Record instance as the input parameter named record. # Any non-Active Record object passed to this implementation is guaranteed to return `false`. return false unless record.is_a?(model) if loaded? || offset_value || limit_value || having_clause.any? records.include?(record) else id = if record.class.composite_primary_key? record.class.primary_key.zip(record.id).to_h else record.id end exists?(id) end end
#last(limit = nil)
Find the last record (or last N records if a parameter is supplied). If no order is defined it will order by primary key.
Person.last # returns the last object fetched by SELECT * FROM people
Person.where(["user_name = ?", user_name]).last
Person.order("created_on DESC").offset(5).last
Person.last(3) # returns the last three objects fetched by SELECT * FROM people.
Take note that in that last case, the results are sorted in ascending order:
[#<Person id:2>, #<Person id:3>, #<Person id:4>]
and not:
[#<Person id:4>, #<Person id:3>, #<Person id:2>]
# File 'activerecord/lib/active_record/relation/finder_methods.rb', line 202
def last(limit = nil) return find_last(limit) if loaded? || has_limit_or_offset? result = ordered_relation.limit(limit) result = result.reverse_order! limit ? result.reverse : result.first end
#last!
Same as #last but raises RecordNotFound
if no record is found. Note that #last!
accepts no arguments.
# File 'activerecord/lib/active_record/relation/finder_methods.rb', line 213
def last! last || raise_record_not_found_exception! end
#member?(record)
Alias for #include?.
# File 'activerecord/lib/active_record/relation/finder_methods.rb', line 407
alias :member? :include?
#ordered_relation (private)
[ GitHub ]# File 'activerecord/lib/active_record/relation/finder_methods.rb', line 640
def ordered_relation if order_values.empty? && (model.implicit_order_column || !model.query_constraints_list.nil? || primary_key) order(_order_columns.map { |column| table[column].asc }) else self end end
#raise_record_not_found_exception!(ids = nil, result_size = nil, expected_size = nil, key = primary_key, not_found_ids = nil)
This method is called whenever no records are found with either a single id or multiple ids and raises an RecordNotFound
exception.
The error message is different depending on whether a single id or multiple ids are provided. If multiple ids are provided, then the number of results obtained should be provided in the result_size
argument and the expected number of results should be provided in the expected_size
argument.
# File 'activerecord/lib/active_record/relation/finder_methods.rb', line 417
def raise_record_not_found_exception!(ids = nil, result_size = nil, expected_size = nil, key = primary_key, not_found_ids = nil) # :nodoc: conditions = " [#{arel.where_sql(model)}]" unless where_clause.empty? name = model.name if ids.nil? error = +"Couldn't find #{name}" error << " with#{conditions}" if conditions raise RecordNotFound.new(error, name, key) elsif Array.wrap(ids).size == 1 error = "Couldn't find #{name} with '#{key}'=#{ids}#{conditions}" raise RecordNotFound.new(error, name, key, ids) else error = +"Couldn't find all #{name.pluralize} with '#{key}': " error << "(#{ids.join(", ")})#{conditions} (found #{result_size} results, but was looking for #{expected_size})." error << " Couldn't find #{name.pluralize(not_found_ids.size)} with #{key.to_s.pluralize(not_found_ids.size)} #{not_found_ids.join(', ')}." if not_found_ids raise RecordNotFound.new(error, name, key, ids) end end
#second
Find the second record. If no order is defined it will order by primary key.
Person.second # returns the second object fetched by SELECT * FROM people
Person.offset(3).second # returns the second object from OFFSET 3 (which is OFFSET 4)
Person.where(["user_name = :u", { u: user_name }]).second
# File 'activerecord/lib/active_record/relation/finder_methods.rb', line 223
def second find_nth 1 end
#second!
Same as #second but raises RecordNotFound
if no record is found.
# File 'activerecord/lib/active_record/relation/finder_methods.rb', line 229
def second! second || raise_record_not_found_exception! end
#second_to_last
Find the second-to-last record. If no order is defined it will order by primary key.
Person.second_to_last # returns the second-to-last object fetched by SELECT * FROM people
Person.offset(3).second_to_last # returns the second-to-last object from OFFSET 3
Person.where(["user_name = :u", { u: user_name }]).second_to_last
# File 'activerecord/lib/active_record/relation/finder_methods.rb', line 319
def second_to_last find_nth_from_last 2 end
#second_to_last!
Same as #second_to_last but raises RecordNotFound
if no record is found.
# File 'activerecord/lib/active_record/relation/finder_methods.rb', line 325
def second_to_last! second_to_last || raise_record_not_found_exception! end
#sole
Finds the sole matching record. Raises RecordNotFound
if no record is found. Raises SoleRecordExceeded
if more than one record is found.
Product.where(["price = %?", price]).sole
# File 'activerecord/lib/active_record/relation/finder_methods.rb', line 143
def sole found, undesired = first(2) if found.nil? raise_record_not_found_exception! elsif undesired.nil? found else raise ActiveRecord::SoleRecordExceeded.new(model) end end
#take(limit = nil)
Gives a record (or N records if a parameter is supplied) without any implied order. The order will depend on the database implementation. If an order is supplied it will be respected.
Person.take # returns an object fetched by SELECT * FROM people LIMIT 1
Person.take(5) # returns 5 objects fetched by SELECT * FROM people LIMIT 5
Person.where(["name LIKE '%?'", name]).take
# File 'activerecord/lib/active_record/relation/finder_methods.rb', line 128
def take(limit = nil) limit ? find_take_with_limit(limit) : find_take end
#take!
Same as #take but raises RecordNotFound
if no record is found. Note that #take!
accepts no arguments.
# File 'activerecord/lib/active_record/relation/finder_methods.rb', line 134
def take! take || raise_record_not_found_exception! end
#third
Find the third record. If no order is defined it will order by primary key.
Person.third # returns the third object fetched by SELECT * FROM people
Person.offset(3).third # returns the third object from OFFSET 3 (which is OFFSET 5)
Person.where(["user_name = :u", { u: user_name }]).third
# File 'activerecord/lib/active_record/relation/finder_methods.rb', line 239
def third find_nth 2 end
#third!
Same as #third but raises RecordNotFound
if no record is found.
# File 'activerecord/lib/active_record/relation/finder_methods.rb', line 245
def third! third || raise_record_not_found_exception! end
#third_to_last
Find the third-to-last record. If no order is defined it will order by primary key.
Person.third_to_last # returns the third-to-last object fetched by SELECT * FROM people
Person.offset(3).third_to_last # returns the third-to-last object from OFFSET 3
Person.where(["user_name = :u", { u: user_name }]).third_to_last
# File 'activerecord/lib/active_record/relation/finder_methods.rb', line 303
def third_to_last find_nth_from_last 3 end
#third_to_last!
Same as #third_to_last but raises RecordNotFound
if no record is found.
# File 'activerecord/lib/active_record/relation/finder_methods.rb', line 309
def third_to_last! third_to_last || raise_record_not_found_exception! end
#using_limitable_reflections?(reflections) ⇒ Boolean
(private)
# File 'activerecord/lib/active_record/relation/finder_methods.rb', line 487
def using_limitable_reflections?(reflections) reflections.none?(&:collection?) end