Rails display table data

Question

I have developed rails app with three classes.

class Location < ActiveRecord::Base
    has_many :observations

end

class Observation < ActiveRecord::Base
  belongs_to :location
  has_one :rainfall
  has_one :temperature
  has_one :winddirection
  has_one :windspeed
  has_one :dewpoint

end


class Rainfall < ActiveRecord::Base
  belongs_to :observation

end

Railfall is related to Observation through an observation_id and Observation is related to Location through a location_id.

If i go to console and type something like: Location.all.first.observations.first.rainfall.value it returns me the data in value column of rainfall

However when i want to combine all the info in rails in a table and in my view/location/index.html.erb i put:

<tbody>
    <% @locations.each do |location| %>
      <tr>

        <td><%= location.name %></td>



        <% unless @observations = nil %>

        <% location.observations.each do |obs| %>
        <td><%= obs.name %></td>

        <% unless @rainfalls = nil %>
        <td><%= obs.rainfalls.value %></td>


    <% end %>
    <% end %>

I get an error:

    undefined method `rainfalls' for Observation:0x00000004219068>

I have spent the last 5 hours trying just about everything i can and am getting a tad frustrated....any ideas?

Note i have a locations controller but observation and rainfall were generated as models, so do not. Am thinking i need to add something to my location controller, just can't work out what, and I am unsure why it returns the correct data in console, just no in app.

Answer 1

Observation.has_one :rainfall, so it should be:

<%= obs.rainfall.value %>

Answer 2

You have one to one relationship, not has_many. Replace

 <%= obs.rainfalls.value %>

by

 <%= obs.rainfall.value %>