Rails查看具有相同外键的所有记录

Question

Currently in my view for each customer I have this:

<p>
  <b>Companyname:</b>
  <%= @customer.companyname %>
</p>

<p>
  <b>Licensecontact:</b>
  <%= @customer.licensecontact %>
</p>

<p>
  <b>Email:</b>
  <%= @customer.email %>
</p>

<p>
  <b>Phone:</b>
  <%= @customer.phone %>
</p>

Under that i need to have a table showing all of the licenses associated with that particular customer. something like this:

<% @licenses.each do |l| %>
<tr>
    <td><%= l.software.vendor %></td>
    <td><%= l.software.title %></td>
    <td><%= l.software.edition %></td>
    <td><%= l.amount %></td>
</tr>
<% end %>

I have three tables, customers, licenses and softwares (I know they're named badly) and one license has many customers and many softwares.

Answer 1

Have you done any tutorials?

1. Your text contradicts you: you say 'One license has many softwares', but your code says 'License l has one software, and I want to display the name, title and edition'.
2. Use belongs_to and has_many. On which tables I cannot tell you, because your code syas the opposite of the last line you write. But these keywords you need to lookup in the docs, to understand how they work and which migrations to make.

Then, if you made the relations in the Models, then you can just call it the way you wrote it down in your second code-part.

Answer 2

You should be able to put something like this into your view:

<table>
  <tr>
    <th>Vendor</th>
    <th>Title</th>
    <th>Edition</th>
    <th>Amount</th>
  </tr>
  <% @customer.licenses.each do |l| %>
    <tr>
      <td><%= l.software.vendor %></td>
      <td><%= l.software.title %></td>
      <td><%= l.software.edition %></td>
      <td><%= l.amount %></td>
    </tr>
  <% end %>
</table>

From your description it's unclear how customers and licenses are linked together. One option is customer has many licenses, license belongs to one user:

class Customer < ActiveRecord::Base
  has_many :licenses
  # ...
end


class License < ActiveRecord::Base
  belongs_to :customer
  # ...
end

another option is HABTM (you've said 'one license has many customers' and 'table showing all of the licenses associated with that particular customer' which hints me to this):

class Customer < ActiveRecord::Base
  has_and_belongs_to_many :licenses
  # ...
end


class License < ActiveRecord::Base
  has_and_belongs_to_many :customers
  # ...
end