由于新的rails生成后，由于rails4("@ emil-kampp"提到了此参数)中的强参数"，您可能会在日志中得到Unpermitted parameters:.它们是在您的控制器中生成的.因此，使用您的代码看起来像:

You're probably getting an Unpermitted parameters: in your log due to Strong Parameters in rails4 (@emil-kampp mentioned this), after a fresh rails generate, they are generated in your controller. So using your code it would look something like:

class EmployersController < ApplicationController
  # <snip>
  def update
    @employer.update(employer_params)
  end

  def employer_params
    params.require(:employer).permit(:name, { :employer_ids => [] })
  end
end

也请参见问题可以回答这个问题.希望这可以节省一些人的时间.

Also see this Question on SO which answers this. Hopefully this saves someone a few cycles.