Redmine

class RemoveOrphanedCustomValueAttachments < ActiveRecord::Migration[7.1]

  def up

    Attachment.where(container_type: 'CustomValue')

              .where('NOT EXISTS (SELECT 1 FROM custom_values WHERE custom_values.id = attachments.container_id)')

              .destroy_all

  end

  def down

    # no-op

  end

end