# A problem about routing request

**URL:** <https://www.ruby-forum.com/t/a-problem-about-routing-request/164352>\
**Category:** Rails\
**Created:** [March 31, 2009, 12:53pm UTC](https://www.ruby-forum.com/t/a-problem-about-routing-request/164352 "2009-03-31T12:53:26Z")\
**Posts on this page:** 3\
**Page:** 1

<div class="post-metadata">

**Author:** ![youhaodeyi](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/y/b9bd4f/32.png) [@youhaodeyi](https://www.ruby-forum.com/u/youhaodeyi)\
**Post date:** [March 31, 2009, 12:53pm UTC](https://www.ruby-forum.com/t/a-problem-about-routing-request/164352/1 "2009-03-31T12:53:26Z")

</div>

I created a scaffold and generated index, new, show, update, destory  
actions and its related views. When I open the index view, I will got  
the error:

You have a nil object when you didn’t expect it!  
The error occurred while evaluating nil.to\_sym

Extracted source (around line #15):

12:

\<%=h db.project\_name %\>  
13: \<%=h db.db\_project %\>  
14: \<%=h db.db\_product %\>  
15: \<%= link\_to ‘Show’, db %\>

there is no problem for other controllers in this rails server. It seems  
that rails failed to request routing. Does anyone have this experience?

---

<div class="post-metadata">

**Author:** ![youhaodeyi](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/y/b9bd4f/32.png) [@youhaodeyi](https://www.ruby-forum.com/u/youhaodeyi)\
**Post date:** [March 31, 2009, 3:15pm UTC](https://www.ruby-forum.com/t/a-problem-about-routing-request/164352/2 "2009-03-31T15:15:30Z")

</div>

Zhao Yi wrote:

> You have a nil object when you didn’t expect it!  
> The error occurred while evaluating nil.to\_sym

贴出错误信息全文好查一点.

---

<div class="post-metadata">

**Author:** ![youhaodeyi](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/y/b9bd4f/32.png) [@youhaodeyi](https://www.ruby-forum.com/u/youhaodeyi)\
**Post date:** [April 1, 2009, 2:51am UTC](https://www.ruby-forum.com/t/a-problem-about-routing-request/164352/3 "2009-04-01T02:51:30Z")

</div>

Nanyang Z. wrote:

> Zhao Yi wrote:
> 
> > You have a nil object when you didn’t expect it!  
> > The error occurred while evaluating nil.to\_sym
> 
> 贴出错误信息全文好查一点.

The error track is shown below.

/usr/local/lib/ruby/gems/1.8/gems/actionpack-2.1.2/lib/action\_controller/routing/route.rb:145:in  
`extra_keys' /usr/local/lib/ruby/gems/1.8/gems/actionpack-2.1.2/lib/action_controller/routing/route.rb:145:in`map’  
/usr/local/lib/ruby/gems/1.8/gems/actionpack-2.1.2/lib/action\_controller/routing/route.rb:145:in  
`extra_keys' generated code (/usr/local/lib/ruby/gems/1.8/gems/actionpack-2.1.2/lib/action_controller/routing/route.rb:45):3:in`generate’  
/usr/local/lib/ruby/gems/1.8/gems/actionpack-2.1.2/lib/action\_controller/routing/route\_set.rb:338:in  
`generate' /usr/local/lib/ruby/gems/1.8/gems/actionpack-2.1.2/lib/action_controller/url_rewriter.rb:131:in`rewrite\_path’  
/usr/local/lib/ruby/gems/1.8/gems/actionpack-2.1.2/lib/action\_controller/url\_rewriter.rb:110:in  
`rewrite_url' /usr/local/lib/ruby/gems/1.8/gems/actionpack-2.1.2/lib/action_controller/url_rewriter.rb:88:in`rewrite’  
/usr/local/lib/ruby/gems/1.8/gems/actionpack-2.1.2/lib/action\_controller/base.rb:622:in  
`url_for' /usr/local/lib/ruby/gems/1.8/gems/actionpack-2.1.2/lib/action_view/helpers/url_helper.rb:71:in`send’  
/usr/local/lib/ruby/gems/1.8/gems/actionpack-2.1.2/lib/action\_view/helpers/url\_helper.rb:71:in  
`url_for' (eval):17:in`ddts\_path’  
app/views/ddts/index.html.erb:15:in  
`_run_erb_47app47views47ddts47index46html46erb' app/views/ddts/index.html.erb:10:in`each’  
app/views/ddts/index.html.erb:10:in  
`_run_erb_47app47views47ddts47index46html46erb' app/controllers/ddts_controller.rb:7:in`index’