如何在Ruby on Rails中传递控制器参数

当我写一个消息，并按下发送选项时，我想存储student_id，coach_id并message到数据库中。student_id并且coach_id正在保存，但未保存该message字段。它在数据库中显示为空。我该如何解决？

任何帮助表示赞赏。

控制器文件：

class CourseQueriesController <ApplicationController
  def index 
    @course_query = CourseQuery.new
  end

  def create
    # @course_query = CourseQuery.new(course_query_params)
    @course_query = CourseQuery.where(student_id: current_student.id, coach_id: "2", message: params[:message]).first_or_create 
    if @course_query.save
      redirect_to course_queries_path, notice: 'Query was successfully send.'
    else
      render :new
    end
  end

  private

  def set_course_query
    @course_query = CourseQuery.find(params[:id])
  end

  # def course_query_params
  #   params[:course_query].permit(:message)
  # end
end

型号/course_query.rb：

class CourseQuery < ActiveRecord::Base
  belongs_to :student
  belongs_to :coach
end

view / course_query / index.html.erb：

<%= simple_form_for (@course_query) do |f| %>
<%= f.button :submit , "Send or press enter"%>
<%= f.input :message %>
<% end %>

数据库/ course_queries：