How do I delete multiple records with dependent records in ActiveRecord

Question

create table foo (id, name, order, ...);
create table foo_bar (id, foo_id, name, value);

foo contains order column with values as (1,2,3,4,5,...10) assuming foo_bar contains multiple records for each foo.

How do I delete foos whose order values are 3..6 and its dependent records?

Answer 1

class Foo < ActiveRecord::Base
  has_many :foo_bars,  :dependent => :destroy
end

class FooBar < ActiveRecord::Base
  belongs_to  :foo
end

If your relation is like above following code will work

Foo.delete_all(["id in (?)", [3,4,5,6]])

OR Just

Foo.delete([3,4,5,6])

Ref delete

EDITED

From little i know your question i think you have something like following

foo table

id  some_column    order
1   some_value      3
2   some_value      4
3   some_value      3
4   some_value      2
5   some_value      1
6   some_value      5
7   some_value      6

foo_bar table

id  some_column    foo_id
1   some_value      2
2   some_value      1
3   some_value      3
4   some_value      2
5   some_value      4
6   some_value      5
7   some_value      6

Then user following order instead of id

Foo.delete_all(["order in (?)", [3,4,5,6]])

Answer 2

The correct answer, to destroy(delete) the dependens:

As @Salil said if your model has the dependent callback like this:

has_many :foo_bars,  :dependent => :destroy

Your query to destroy the parent and dependent records should be:

Foo.where(order: [1, 2, 3, 4]).destroy_all

The method where will get all records with the array of orders and call the destroy method for each record found.

JUST USE delete or delete_all if you don't want to execute the callbacks about destroy dependencies.