using find to get the value from a table referenced by foreign key

rubyonrails-talk
1

Hello all,

I have 2 tables calls and clients:

clients:

2

Hi,

Following up more on this...

Hello all,

I have 2 tables calls and clients:

clients: +-----------+---------+------+-----+---------+----------------+ > Field | Type | Null | Key | Default | Extra | +-----------+---------+------+-----+---------+----------------+ > id | int(11) | | PRI | NULL | auto_increment | > ivr_id | int(11) | YES | MUL | NULL | | > is_online | char(1) | YES | | NULL | | +-----------+---------+------+-----+---------+----------------+

calls: +-------------+--------------+------+-----+---------+----------------+ > Field | Type | Null | Key | Default | Extra | +-------------+--------------+------+-----+---------+----------------+ > id | int(11) | | PRI | NULL | auto_increment | > src | varchar(80) | YES | | NULL | | > start | datetime | YES | | NULL | | > ivr_id | int(11) | YES | MUL | NULL | | > file_name | varchar(255) | YES | | NULL | | +-------------+--------------+------+-----+---------+----------------+

Here calls.ivr_id is the foreign key referring to clients.ivr_id

Corresponding models are :

class Call < ActiveRecord::Base   belongs_to :client, :foreign_key => "ivr_id"   def self.calls_and_is_online (from_time, to_time)     find (:first,           :conditions => [             "start > :from_time and start <= :to_time              and ivr_id <> 0              and file_name like '%wav'",             {:from_time => from_time, :to_time => to_time}           ])   end end

class Client < ActiveRecord::Base   has_one :call, :foreign_key => "ivr_id" end

My call_controller has a method

  def get_calls_and_is_online     @date = Time.parse(params[:date])     @calls_and_is_online = Call.calls_and_is_online(@date, @date+1.day)   end

From my controller I can get all the details of call table with out any problems. Now I want to get the is_online status of a call. The rails book Chap: 18 says I can define some thing like price = line_item.product.price, but in my case when I use <%= @calls_and_is_online.client.is_online %> from my view, I get the error

NoMethodError in Call#get_calls_and_is_online

I added the following in my view:

<%= xx = Call.find (56755) %> <%= debug(xx.client.class) %>

<%= yy = Client.find(41842) %> <%= debug (yy.call.class) %>

The corresponding sql queries are:   Call Columns (0.000880) SHOW FIELDS FROM calls   Call Load (0.000436) SELECT * FROM calls WHERE (calls.id = 56755) LIMIT 1   Client Load (0.000318) SELECT * FROM clients WHERE (clients.id = 17575) LIMIT 1   Client Load (0.000303) SELECT * FROM clients WHERE (clients.id = 41842) LIMIT 1   Client Columns (0.000466) SHOW FIELDS FROM clients   Call Load (0.052974) SELECT * FROM calls WHERE (calls.ivr_id = 41842)

The corresponding values in datbase are:

SELECT ivr_id FROM calls WHERE (calls.id = 56755) LIMIT 1

3

I have finally fixed this:

I was over riding the rails configuration at two places.

1. Primary key in Clients table is ivr_id instead of id 2. Foreign key referreng to clients table is ivr_id instead of client_id

So this involves letting rails know that I have overridden the conventions at 2 places,

1. in Clients.rb use set_primary_key "ivr_id" so that rails know that the primary key is ivr_id instead of id 2. in Calls.rb use belongs_to :client, :foreign_key => "ivr_id" so that rails know that it should use ivr_id instead of client_id

The actuall files are

class Call < ActiveRecord::Base   belongs_to :client, :foreign_key => "ivr_id"

class Client < ActiveRecord::Base   set_primary_key "ivr_id"   has_many :calls

Thanks every one,

raj