Question

I have

class List < ActiveRecord::Base
  has_many :list_items

class ListItem < ActiveRecord::Base
  belongs_to :list

I want to select all lists of a certain type and then delete all the associated list_items. I’ve tried map and some other things but stuck.

List.where('list_type_id=4').?

I know this should be a one-liner but ?

thx

** edit #1**

SyntaxError: (irb):94: syntax error, unexpected tCONSTANT, expecting ')'
...ListItem.where('list_id = ?' List.where('list_type_id=4').id)....
...                               ^
(irb):94: syntax error, unexpected ')', expecting $end
...ist.where('list_type_id=4').id).destroy_all
...                               ^

Answer 1

For posterity,

List.where('list_type_id=4').map(&:list_items).flatten.each {|li| li.delete }

but yeah, feels like there should be a Railsier way to do it.