Problem With Active Record. Associations Showing Error ..ple

Rails
1

i am stuck somewhere with The Acrive record association .
whenever i try to get the value from another table it gives me the
foolowing error
“undefined method `journal_name’ for nil:NilClass”

MY Controller

def index
@ledgers = Ledger.find(:all)
@finaccounts = Finaccount.find(:all)
@journels = Journel.all
respond_to do |format|
format.html
format.pdf { render :layout => false }
end

view:

<td><%=h ledger.journel.journal_name %></td>

Models :

  1. Journel

class Journel < ActiveRecord::Base
has_many :ledgers
end

class Ledger < ActiveRecord::Base
belongs_to :journel
end

2

Apparently one or more of your ledgers doesn’t have a journel?

Try:

<%=h ledger.journel.journal_name if ledger.journel %> to see the ones that don't have journels.
3

Thanks For the Help Heinz S…
But i need To Know Is there anything with rails 2.3.5 because to check
wheather i have made any mistake in my application i created a sample
application , and again it was the same error i got .
waiting for your reply
and one more thing …i am only a couple of months old to Ruby On rails
.so please if possible suggest me how to make the associations between
tables in rails.

4

If you are much interested in Rails Associations means, refer these
URLs.

–
Regards,

T.Veerasundaravel.
http://tinyurl.com/25vma7h
@veerasundaravel

Sudhir V. wrote:

Thanks For the Help Heinz S…
But i need To Know Is there anything with rails 2.3.5 because to check
wheather i have made any mistake in my application i created a sample
application , and again it was the same error i got .
waiting for your reply
and one more thing …i am only a couple of months old to Ruby On rails
.so please if possible suggest me how to make the associations between
tables in rails.

5

Sorry But I guess I have read all The Associations …the only thing i
want to know is there any problem with rails 2.3.5 because when i make
the associations in 2.3.5 i get the same error
undefined method `some method’ for nil:NilClass"

Veera S. wrote:

If you are much interested in Rails Associations means, refer these
URLs.

Active Record Associations — Ruby on Rails Guides
ActiveRecord::Associations::ClassMethods

–
Regards,

T.Veerasundaravel.
http://tinyurl.com/25vma7h
@veerasundaravel

Sudhir V. wrote:

Thanks For the Help Heinz S…
But i need To Know Is there anything with rails 2.3.5 because to check
wheather i have made any mistake in my application i created a sample
application , and again it was the same error i got .
waiting for your reply
and one more thing …i am only a couple of months old to Ruby On rails
.so please if possible suggest me how to make the associations between
tables in rails.

6

On Fri, Sep 17, 2010 at 3:31 PM, Sudhir V.
[email protected]wrote:

Sorry But I guess I have read all The Associations …the only thing i
want to know is there any problem with rails 2.3.5 because when i make
the associations in 2.3.5 i get the same error
undefined method `some method’ for nil:NilClass"

You can use “rails console” to start up the RAILS console and look up
the
values of various objects and make a decision why you are getting null.
Most probable reason why you are getting null is that “journel_id” value
is
not set in Ledger records.

In RAILS console, do:

Ledger.first
…observe the field values…, look wheher journel_id has valid integer

Ledger.first.journel
…if you get null, then, journel_id is not correct. try to set it to a
valid jourenl

lg = Ledger.first
lg.journel = Journel.first
lg.save!
Ledger.first.jourenl
…now you should not see null…

Regards,

application , and again it was the same error i got .
“Ruby on Rails: Talk” group.
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For more options, visit this group at
http://groups.google.com/group/rubyonrails-talk?hl=en.

–
Srikanth S.
http://www.srikanthps.com
@srikanthps

7

On Sep 17, 11:01 am, Sudhir V. [email protected] wrote:

Sorry But I guess I have read all The Associations …the only thing i
want to know is there any problem with rails 2.3.5 because when i make
the associations in 2.3.5 i get the same error
undefined method `some method’ for nil:NilClass"

Unlikely. As Heinz said, the most likely explanation is that some of
your ledgers don’t have a journel.

Fred

8

I doubt there’s a problem with Rails 2.3.5

Fire up the console and try following:
ledger = Ledger.first
ledger.journel = Journel.first
ledger.journel.journal_name

This should work and if so the ledgers you’re calling in the view just
doesn’t have a journel. If not something’s wrong with the whole thing :slight_smile: