I'm trying to put together a form_tag that edits several Shift objects. I have the form built properly, and it's passing on the correct parameters. I have verified that the parameters work with updating the objects correctly in the console. However, when I click the submit button, I get the error:

ActiveRecord::RecordNotFound in ShiftsController#update_individual
Couldn't find Shift without an ID

My route for the controller it is calling looks like this looks like this:

map.resources :shifts, :collection => { :update_individual => :put }

The method in ShiftsController is this:

def update_individual
  Shift.update(params[:shifts].keys, params[:shifts].values)
  flash[:notice] = "Schedule saved"
end

The relevant form parts are these:

<% form_tag( update_individual_shifts_path ) do %> 
  ... (fields for...)
  <%= submit_tag "Save" %>  
<% end %>

Why is this not working? If I browse to the url: "http://localhost:3000/shifts/update_individual/5" (or any number that corresponds to an existing shift), I get the proper error about having no parameters set, but when I pass parameters without an ID of some sort, it errors out.

How do I make it stop looking for an ID at the end of the URL?