CODEWITHSUNDEEP
ruby-on-rails
Jonah Katz
Jonah Katz

Reputation: 5288

Get the parent of a child in a has_many relationship?

Im creating a RoR app to manage a basketball league. I have two tables: teams & games. Its set up that each team has many games. Each row in games contains two foreign keys; one for home team, and one for away team. I have the following code to list the data in the games table:

<% @games.each do |game| %>
  <tr>
    <td><%= game.home_team_id %></td>
    <td><%= game.away_team_id %></td>
    <td><%= game.home_team_score %></td>
    <td><%= game.away_team_score %></td>
    <td><%= game.date %></td>
  </tr>
<% end %>

However, the first two parts dont work, presumably because is used the format when calling an objects child. But here, im trying to call the child's parent (game.home_team_id)

How do you get the parent of a child?

Here's my Game model:

class Game < ActiveRecord::Base
  belongs_to :team, :foreign_key => "home_team"
  belongs_to :team, :foreign_key => "away_team"
  has_many :stats

end

Upvotes: 0

Views: 1141

Answers (1)

Ben Miller
Ben Miller

Reputation: 1484

If the column names are as you specified in your view, you should be seeing the IDs.

Typically, in you game model you would do

belongs_to :home_team, :class_name=>"Team"
belongs_to :away_team, :class_name=>"Team"

then in your view, you would do

<td><%= game.home_team.name %></td>
<td><%= game.away_team.name %></td>

If you aren't seeing at the IDs as it is, i would check that the values are being set.

In console, just do:

Game.first.inspect

If the team ids are empty, we have found the source of this error. Which hints at a problem in your create method.

Upvotes: 3

Related Questions