Rails 5: Displaying object value not ID - ruby-on-rails

Question

I have a simple app for a skydiving dropzone. Parachute packers keep track of their packsjobs. There are several packjobs for each parachute rig.
I have the Show view working perfectly by showing the rig_type_number under the rig detail (ie Reflex #2) but I can only get the rig_id to work in the same column for the index. Ideally, I'd like to so the rig_type_number as well instead of the ID.
How can I reference in the view something to the effect of #rigs.rig_type_number?
This makes sense to me, but does not work:
<td><%= link_to packjob.rig_id,rig_path(rig.rig_type_number) %>
Will I have to a where clause for the index controller?
db:
class CreatePackjobs < ActiveRecord::Migration[5.1]
def change
create_table :packjobs do |t|
t.string :packer
t.string :rig
t.references :rig, foreign_key: true
t.timestamps
end
end
end
class CreateRigs < ActiveRecord::Migration[5.1]
def change
create_table :rigs do |t|
t.boolean :rig_status
t.string :rig_type_number
t.integer :rig_season_jumpnum
t.date :rig_res_last
t.string :rig_res_who
t.timestamps
end
end
end
packjobs_controller:
class PackjobsController < ApplicationController
def index
#packjobs = Packjob.paginate(page: params[:page]).order('id DESC')
#rigs = Rig.where(rig_status: "t")
end
def show
#packjob = Packjob.find(params[:id])
#rig = Rig.find(#packjob.rig_id)
end
def new
#packjob = Packjob.new
#rigs = Rig.where(rig_status: "t")
end
def edit
#packjob = Packjob.find(params[:id])
#rigs = Rig.where(rig_status: "t")
end
def create
#packjob = Packjob.new(packjob_params)
#rigs = Rig.where(rig_status: "t")
if #packjob.save
redirect_to #packjob
else
render 'new'
end
end
def update
#packjob = Packjob.find(params[:id])
#rigs = Rig.where(rig_status: "t")
if #packjob.update(packjob_params)
redirect_to #packjob
else
render 'edit'
end
end
def destroy
#packjob = Packjob.find(params[:id])
#packjob.destroy
redirect_to packjobs_path
end
private
def packjob_params
params.require(:packjob).permit(:packer, :rig_id)
end
def rigs_params
params.require(:rig).permit(:rig_status, :rig_type_number)
end
end
show.html.erb:
<p>
<b>Datestamp:</b>
<%= #packjob.created_at.strftime("%m/%d/%Y %I:%M %P") %><br>
</p>
<p>
<strong>Packer:</strong>
<%= #packjob.packer %>
</p>
<p>
<strong>Rig:</strong>
<%= #rig.rig_type_number %><br>
</p>
<%= link_to 'Edit', edit_packjob_path(#packjob) %> |
<%= link_to 'Back', packjobs_path %>
index.html.erb:
<h1>Listing Packjobs</h1>
<%= link_to 'New Packjob', new_packjob_path %> | <br>
<br>
<div class="digg_pagination">
<%= will_paginate #packjobs, :container => false %>
</div>
<table id=listtable CELLPADDING="4" border="1">
<tr class="headerBlue" >
<th>Datestamp</th>
<th>Packer</th>
<th>Rig</th>
<th colspan="3"></th>
</tr>
<% #packjobs.each do |packjob| %>
<tr class="<%= cycle('rowA', 'rowB') %>">
<td><%= link_to packjob.created_at.strftime("%m/%d/%Y %I:%M:%S %P"),packjob_path(packjob.id) %></td>
<td><%= packjob.packer %></td>
<td><%= link_to packjob.rig_id,rig_path(packjob.rig_id) %>
<td><%= link_to 'Show', packjob_path(packjob) %></td>
<td><%= link_to 'Edit', edit_packjob_path(packjob) %></td>
<td><%= link_to 'Destroy', packjob_path(packjob),
method: :delete,
data: { confirm: 'Are you sure?' } %></td>
<% end %>
</tr>
</table>
<div class="digg_pagination">
<div class="page_info">
<%= page_entries_info #packjobs %>
</div>
<%= will_paginate #packjobs, :container => false %>
</div>
<br><%= link_to 'New Packjob', new_packjob_path %> |
EDITED:
models:
class Packjob < ApplicationRecord
belongs_to :rig
validates :packer, presence: true
validates :rig_id, presence: true
self.per_page = 25
end
class Rig < ApplicationRecord
has_many :packjobs
validates :rig_type_number, presence: true
self.per_page = 25
end

Answer 1

Your associations are set correctly, you can reference the associated object like this:
<td><%= link_to packjob.rig.rig_type_number,rig_path(packjob.rig_id) %>

Answer 2

You can call it as below in case you have has_one :rig association in PackJob model :
<td><%= link_to packjob..rig.rig_type_number,rig_path(packjob.rig_id) if packjob.rig.present? %> </td>