# Betternestedset in rails 3.0

**URL:** <https://www.ruby-forum.com/t/betternestedset-in-rails-3-0/184776>\
**Category:** Rails\
**Created:** [March 8, 2010, 2:16pm UTC](https://www.ruby-forum.com/t/betternestedset-in-rails-3-0/184776 "2010-03-08T14:16:00Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![vmvipin](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/v/c0e974/32.png) [@vmvipin](https://www.ruby-forum.com/u/vmvipin)\
**Post date:** [March 8, 2010, 2:16pm UTC](https://www.ruby-forum.com/t/betternestedset-in-rails-3-0/184776/1 "2010-03-08T14:16:00Z")

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Hi Guys,

when i upgraded my rails 2.3.4 to 3.0 my betternestedset is not working.  
It was working fine in the older version. This is my controller

def new  
cat = Category.new  
cat.text=‘test’  
cat.save  
cat.move\_to\_child\_of(Category.find\_by\_id(1)) #26  
redirect\_to :action =\> ‘index’  
end

It gives me this error : “You cannot move a node if left or right is  
nil”  
app/controllers/categories\_controller.rb:26:in `new’

Database looks like this :

## “id” “parent\_id” “lft” “rgt” “text”

“1” “NULL” “1” “2” “1000”  
“2” “NULL” “NULL” “NULL” “abcd”

Thanks in advance

Vipin