form_for
params.require(:classname).permit(:field1, :field2)
<%= form_for @school_class do |f| %>
<%= f.text_field :title %>
<%= f.number_field :room_number %>
<% end %>
form_for
params.require(:classname).permit(:field1, :field2)
<%= form_for @school_class do |f| %>
<%= f.text_field :title %>
<%= f.number_field :room_number %>
<% end %>