delete(*records)
Instance Public methods
Deletes the records supplied and removes them from the
collection. For has_many associations, the deletion is done
according to the strategy specified by the :dependent option.
Returns an array with the deleted records.
If no :dependent option is given, then it will follow the
default strategy. The default strategy is :nullify. This sets
the foreign keys to NULL. For, has_many
:through, the default strategy is delete_all.
class Person < ActiveRecord::Base has_many :pets # dependent: :nullify option by default end person.pets.size # => 3 person.pets # => [ # #<Pet id: 1, name: "Fancy-Fancy", person_id: 1>, # #<Pet id: 2, name: "Spook", person_id: 1>, # #<Pet id: 3, name: "Choo-Choo", person_id: 1> # ] person.pets.delete(Pet.find(1)) # => [#<Pet id: 1, name: "Fancy-Fancy", person_id: 1>] person.pets.size # => 2 person.pets # => [ # #<Pet id: 2, name: "Spook", person_id: 1>, # #<Pet id: 3, name: "Choo-Choo", person_id: 1> # ] Pet.find(1) # => #<Pet id: 1, name: "Fancy-Fancy", person_id: nil>
If it is set to :destroy all the records are
removed by calling their destroy method. See
destroy for more information.
class Person < ActiveRecord::Base has_many :pets, dependent: :destroy end person.pets.size # => 3 person.pets # => [ # #<Pet id: 1, name: "Fancy-Fancy", person_id: 1>, # #<Pet id: 2, name: "Spook", person_id: 1>, # #<Pet id: 3, name: "Choo-Choo", person_id: 1> # ] person.pets.delete(Pet.find(1), Pet.find(3)) # => [ # #<Pet id: 1, name: "Fancy-Fancy", person_id: 1>, # #<Pet id: 3, name: "Choo-Choo", person_id: 1> # ] person.pets.size # => 1 person.pets # => [#<Pet id: 2, name: "Spook", person_id: 1>] Pet.find(1, 3) # => ActiveRecord::RecordNotFound: Couldn't find all Pets with IDs (1, 3)
If it is set to :delete_all, all the records are
deleted without calling their destroy method.
class Person < ActiveRecord::Base has_many :pets, dependent: :delete_all end person.pets.size # => 3 person.pets # => [ # #<Pet id: 1, name: "Fancy-Fancy", person_id: 1>, # #<Pet id: 2, name: "Spook", person_id: 1>, # #<Pet id: 3, name: "Choo-Choo", person_id: 1> # ] person.pets.delete(Pet.find(1)) # => [#<Pet id: 1, name: "Fancy-Fancy", person_id: 1>] person.pets.size # => 2 person.pets # => [ # #<Pet id: 2, name: "Spook", person_id: 1>, # #<Pet id: 3, name: "Choo-Choo", person_id: 1> # ] Pet.find(1) # => ActiveRecord::RecordNotFound: Couldn't find Pet with id=1
You can pass Fixnum or String values, it finds
the records responding to the id and executes delete on them.
class Person < ActiveRecord::Base
has_many :pets
end
person.pets.size # => 3
person.pets
# => [
# #<Pet id: 1, name: "Fancy-Fancy", person_id: 1>,
# #<Pet id: 2, name: "Spook", person_id: 1>,
# #<Pet id: 3, name: "Choo-Choo", person_id: 1>
# ]
person.pets.delete("1")
# => [#<Pet id: 1, name: "Fancy-Fancy", person_id: 1>]
person.pets.delete(2, 3)
# => [
# #<Pet id: 2, name: "Spook", person_id: 1>,
# #<Pet id: 3, name: "Choo-Choo", person_id: 1>
# ]
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