How to retrieve data from a table in rails - ruby-on-rails

Question

I have a table that stores all billing history for each user. I need to display certain fields from this table in an invoice for the user. When I call the variables in my view I get a 'undefined method error'.
Here is a small example of what i have in the view.
<tbody>
<tr>
<td>
Invoice Number
</td>
<td>
<%= #billing_history.id %>
</td>
</tr>
<tr>
<td>
Issue Date
</td>
<td>
<%= #billing_history.created_at.strftime('%d/%m/%Y' ) %>
</td>
</tr>
<tr>
<td>Tax Number</td>
<td>
######
</td>
</tr>
</tbody>
Here is my controller
def invoice
#company = current_user.company
#billing_history = BillingHistory.find_by(id: params[:billing_id])
# raise 'not for you' if #billing_history.company != #company.id
render pdf: 'billings/invoice'
end
Here is my full error message
> `ActionView::Template::Error (undefined method `id' for nil:NilClass):
4: <meta charset="UTF-8" />
5: <meta name="viewport" content="width=device-width, initial-scale=1.0" />
6: <meta http-equiv="X-UA-Compatible" content="ie=edge" />
7: <title>Invoice <%= #billing_history.id %></title>
8: <style>
`

Answer 1

try using byebug place it after
#billing_history = BillingHistory.find_by(id: params[:billing_id]) this line
then check what is the value of #billing_history if it's nil then use The Safe Navigation Operator (&.) like #billing_history&.id ,that won't raise any error.