Question

According to the documentation Rails has_many association has clear method. Looks like it executes sql delete query immediately after it performs. Is there a canonical way to delete all the child objects and update association only at the moment of save method? For example:

@cart.container_items.delete_all_example # looks like `clear` execute sql at this line
if @cart.save
  # do smth
else
  #do smth
end

it is necessary because of many changes at the parent object and they must be committed all or none of them.

Answer 1

Try this:

Cart.transaction do
  @cart.container_items.delete_all_example # looks like `clear` execute sql at this line
  if @cart.save
    # success
  else
    # error
    raise ActiveRecord::Rollback
  end
end

ActiveRecord::Rollback is not propagated outside the transaction block. It simply terminates the transaction.