can anyone help me with showing lists with conditions?

hi i'm trying things out with rails, and I'm having trouble with showing a list of products. i hope someone can help me out with this..

my tables are simple and it contains the following fields

product table : id | Name | Price | Country_id country table : id | CountryName

and I input products info with selected id numbers from the "country" table and insert the country.id into products.Country_id.

I am trying to show countryName from the country table on the products list.

it would be wonderful if anyone can help me out with this..

thank you

Hi,

You must have defined has_many and belongs_to association for Country and Product.

So now you can directly write: @product.country.name

-Hemali Chauhan

Also you will make life much easier for yourself if you stick to the rails naming conventions, so the column names will be id, name, price, country_id and id, country_name.

You might find this helpful http://guides.rubyonrails.org/getting_started.html

Colin

Hi, I'm also new to rails and I'm trying the same thing. I'm extending the Getting Started example to learn.

I've made an extra table called `clients`: (id | name) and I already had the table `posts`: (id | title | content | created_at | updated_at

client_id). The index view for posts loops through all the posts I

want to show the client name. I believe the way to do this is like this:

<% @posts.each do |post| %>   <tr>     <td><%=h post.client.name %></td>     <td><%=h post.title %></td>     [...]

I have set up all the assocations (posts belongs_to client, client has_many posts) but it doesn't work. I'm probably making a simple mistake but hey, I'm new :slight_smile:

Thanks in advance.

How does it fail? What error messages does it give? Please send us your full model code

When asking for help, it's best to give as much context as possible.

Check out my free videos at http://sensei.zenunit.com . They may help.

Julian.

hey.. Thanx Chauhan.. i got it working.. in my case, I used has_one with options..

thanx a bunch :slight_smile:

hey.. ( pepijnlooije@gmail.com )

i hope you got it working by now.. :slight_smile: anyway, I've got my problem solved like this.

i wrote

belongs_to :Country, :foreign_key => :Country_id in products.rb .... it means that the each products belongs to the Country table with the foreign_key of Country_id that matches with id field of the Country table. well, I got it mixed up with has_one and the belongs_to.. ^^ anyway.. then, in the view.html,erb file, i wrote                                                        <%=h product.Country.CountryName %> inside the <%@products.each do..... loop.. %> and i got it working. I hope this makes sense to to you.... I'm new too.. so I'm not sure if I'm on the right track :slight_smile:

well I hope you get yours working with this, or with the better solution

good luck to both of us.. :slight_smile:

This is pretty weird actually, in the show view the name is displayed (nice!!!), but in the index view (the list of all the posts) it isn't working yet. The code for the index view (not working) is as I wrote earlier:

<% @posts.each do |post| %>   <tr>     <td><%=h post.client.name %></td>     <td><%=h post.title %></td>     [...]

The show view (which works) is like this:

<p>   <b>Name:</b>   <%=h @post.client.name %> </p>

The error generated by the index view:

Showing app/views/posts/index.html.erb where line #12 raised:

You have a nil object when you didn't expect it! The error occurred while evaluating nil.name

Good job Mike that you got it working :slight_smile: It's pretty hard for me starting with Rails, coming from a PHP/CodeIgniter background. The convention over configuration is really great though! I also watched some screencasts last night, very useful!

This is pretty weird actually, in the show view the name is displayed

(nice!!!), but in the index view (the list of all the posts) it isn’t

working yet. The code for the index view (not working) is as I wrote

earlier:

<% @posts.each do |post| %>

<td><%=h [post.client.name](http://post.client.name) %></td>

<td><%=h post.title %></td>

[...]

The show view (which works) is like this:

Name:

<%=h @post.client.name %>

The error generated by the index view:

Showing app/views/posts/index.html.erb where line #12 raised:

You have a nil object when you didn’t expect it!

The error occurred while evaluating nil.name

This means that post.client is nil (hence error with post.client.name). Are you sure that all your posts have a client? You could use <%= h post.client.name if post.client %>

which will at least let it show posts that have clients and show nothing for those that have not, while you work out why some (or all) not.

Colin