Connecting several tables in single database

Rails
1

Hi,

Anybody please tell me the tutorial way to connect and retrieve data
using
foreign key in a connected table.

–
With Regards
Palani Kannan. K

2

On 23 September 2010 07:58, PalaniKannan K [email protected]
wrote:

Hi,

Anybody please tell me the tutorial way to connect and retrieve data using
foreign key in a connected table.

I think I may have already answered this in my reply to your other
question, have a look at the Rails Guide on ActiveRecord
Relationships. But probably start with Getting Started guide.

Colin

3

Dear Collin,

I feel that I am not clearly explained you, here I included the clear
explanation about the problem. I included models, controller and View.
Please, find the mistake in it and tell me.

name model
has_many :city, :foreign_key => “name_id”
has_many :country, :foreign_key => “name_id”
*
city model*
belongs_to :name

country model
belongs_to :name

In Name Controller
@names = Name.find(:all, :conditions=>{:first_name => params[:gm],
:second_name => params[:sp]}, :include => [ :city, :country ])

In Name View

<% @names.each do |name| %>
<%= name.age %>
<% end %>

<% @names.cities.each do |city| %>
<%= city.local_area %>
<% end %>

<% @names.countries.each do |country| %>
<%= country.state %>
<% end %>

On 23 September 2010 09:56, Colin L. [email protected] wrote:

Relationships. But probably start with Getting Started guide.
For more options, visit this group at
http://groups.google.com/group/rubyonrails-talk?hl=en.

–
With Regards
Palani Kannan. K

4

PalaniKannan K wrote:

name model
has_many :city, :foreign_key => “name_id”
has_many :country, :foreign_key => “name_id”
*

has_many models should be pluralized

class name < ActiveRecord::Base
has_many :cities
has_many :countries
end

5
6

Hi,

I tried with

In View

<% @names.each do |name| %>
<%= name.age %>
<% name.cities.each do |city| %>
<%= city.local_area %>
<% name.countries.each do |country| %>
<%= country.state %>
<% end %>

This shows no error with no output of city.local_area and country.state

On 23 September 2010 12:45, PalaniKannan K [email protected]
wrote:

city model*

<% end %>

foreign key in a connected table.
To post to this group, send email to [email protected].
With Regards
Palani Kannan. K

–
With Regards
Palani Kannan. K

7

Dear Ar Chron,

Thanks for your correction. The error solved, but its not still showing
the
values for

<%= city.local_area %>
<%= country.state %>

On 23 September 2010 16:30, Ar Chron [email protected] wrote:

has_many :cities
[email protected][email protected]
.
For more options, visit this group at
http://groups.google.com/group/rubyonrails-talk?hl=en.

–
With Regards
Palani Kannan. K

8

Hi,

Extreme sorry for all and Colin, I posted in several thread… I will
not
post repeated posts once again.

–
Palani Kannan

9

On 23 September 2010 16:34, PalaniKannan K [email protected]
wrote:

Why are you asking the same question in multiple threads?

Colin

10

Dear All,

Finally, tables are connecting and displaying data once i provided
“set_primary_key”. I read about role of “foreign key” in connecting
table.
But, I dont know the role of “primary_key” in connecting tables. Anybody
knows it???

–
With Regards,
Palani Kannan. K

11

You are probably getting an “undefined method ‘cities’ for #<Array:blah
blah>” error. Address each hierarchy level in turn…

<% @names.each do |name| %>
<% name.cities.each do |city| %>
<%= city.local_area %>
<% end %>
<% end %>

<% @names.each do |name| %>
<% name.countries.each do |country| %>
<%= country.state %>
<% end %>
<% end %>