c.profile_datum

client profile data

I have a client class

````
class Client < ActiveRecord::Base
  attr_accessible :name, :notetag
  has_many :profile_datum
end
````
..and a ProfileDatum class

````
class ProfileDatum < ActiveRecord::Base
  belongs_to :client, :dependent => :delete
  attr_accessible :address, :emailid, :notes, :phone, :client_id
end
````

I create objects like so:

p1 = ProfileDatum.create(:address => "Mumbai on the manger", :notes => "ever work with him", emailid: "six@dfg.com", :phone => "3434673453")

c = Client.find(2) #this exists

And then I try to associate like this: `c << p1` sometimes it works but most times it doesn't.
When it works,I try to associate like so:
 `c.profile_datum` and it doesn't work #undefined method `profile_datum' for #<Array:>