# Railroad problem

**URL:** <https://www.ruby-forum.com/t/railroad-problem/120399>\
**Category:** Ruby\
**Created:** [November 16, 2007, 3:37pm UTC](https://www.ruby-forum.com/t/railroad-problem/120399 "2007-11-16T15:37:06Z")\
**Posts on this page:** 3\
**Page:** 1

<div class="post-metadata">

**Author:** ![unknown](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/u/4bbf92/32.png) [@unknown](https://www.ruby-forum.com/u/unknown)\
**Post date:** [November 16, 2007, 3:37pm UTC](https://www.ruby-forum.com/t/railroad-problem/120399/1 "2007-11-16T15:37:06Z")

</div>

Hi all,

```
        Got struck up with this. Please help.

```

The actual requirement is that I am trying to generate a model diagram  
thru the railroad which I have installed in my machine. I use both  
oracle and postgre db’s in the db connection (database.yml file).

"puredisk\_development:

adapter: postgresql

database: ca

port: 10085

username: \*\*\*

password: \*\*\*

reporting\_development:

adapter: oracle

username: \*\*\*

password: \*\*\*

database: \*\*\*

"

The error which I am getting when I am running the command “railroad -M  
-v -o models” is

/usr/local/lib/ruby/gems/1.8/gems/activesupport-1.4.2/lib/active\_support  
/dependencies.rb:249:in `load\_missing\_constant’: Expected  
config/…/app/models/pd.rb to define Pd (LoadError)

```
    from

```

/usr/local/lib/ruby/gems/1.8/gems/activesupport-1.4.2/lib/active\_support  
/dependencies.rb:452:in `const\_missing’

```
    from

```

/usr/local/lib/ruby/gems/1.8/gems/activesupport-1.4.2/lib/active\_support  
/dependencies.rb:464:in `const\_missing’

```
    from

```

/usr/local/lib/ruby/gems/1.8/gems/activesupport-1.4.2/lib/active\_support  
/inflector.rb:250:in `constantize’

```
    from

```

/usr/local/lib/ruby/gems/1.8/gems/activesupport-1.4.2/lib/active\_support  
/core\_ext/string/inflections.rb:148:in `constantize’

```
    from

```

/usr/local/lib/ruby/gems/1.8/gems/railroad-0.4.0/lib/railroad/models\_dia  
gram.rb:25:in `generate’

```
    from

```

/usr/local/lib/ruby/gems/1.8/gems/railroad-0.4.0/lib/railroad/models\_dia  
gram.rb:24:in `each’

```
    from

```

/usr/local/lib/ruby/gems/1.8/gems/railroad-0.4.0/lib/railroad/models\_dia  
gram.rb:24:in `generate’

```
    from

```

/usr/local/lib/ruby/gems/1.8/gems/railroad-0.4.0/bin/railroad:40

```
    from /usr/local/bin/railroad:16:in `load'

    from /usr/local/bin/railroad:16

```

This “pd.rb” in the error uses the postgre db conection.

The contents of the pd.rb file are

"

class PD \< ActiveRecord::Base

connection = “puredisk\_#{ENV[‘RAILS\_ENV’]}”

establish\_connection connection.to\_sym

end

class PD::Policy \< PD; set\_table\_name ‘policy’; end

class PD::Dsinpolicies \< PD; set\_table\_name ‘dsinpolicies’; end

class PD::Dataselection \< PD; set\_table\_name ‘dataselection’; end

class PD::Agent \< PD; set\_table\_name ‘agent’; end

class PD::Job \< PD; set\_table\_name ‘job’; end

class PD::Policyrun \< PD; set\_table\_name ‘policyrun’; end

class PD::Dstemplate \< PD; set\_table\_name ‘dataselectiontemplate’; end

class PD::Policytype \< PD; set\_table\_name ‘policytype’; end

"

And the rails\_env is “development”

Thanks in advance …

Regards,

Anand.

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---

<div class="post-metadata">

**Author:** ![unknown](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/u/4bbf92/32.png) [@unknown](https://www.ruby-forum.com/u/unknown)\
**Post date:** [November 16, 2007, 3:52pm UTC](https://www.ruby-forum.com/t/railroad-problem/120399/2 "2007-11-16T15:52:20Z")

</div>

removed\_email\_address@domain.invalid wrote:

> oracle and postgre db’s in the db connection (database.yml file).
> 
> username: \*\*\*
> 
> establish\_connection connection.to\_sym
> 
> end

Do you have an environment called ‘development’ in database.yml? It  
seems you have reporting\_development and puredisk\_development but not  
development.

That said, I think for one of my projects, I had some problems with  
railroad trying to resolve class name because my file names didn’t seem  
to match the convention… I think my table was called TTFiles and my  
model was TtFile and the file name was tt\_file.rb - and it all didn’t  
add up to Railroad properly at that time. I don’t know if the problem  
you are seeing is because it expects your class to be Pd (not PD)?

Hope this helps.

Cheers,  
Mohit.  
11/16/2007 | 10:51 PM.

---

<div class="post-metadata">

**Author:** ![unknown](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/u/4bbf92/32.png) [@unknown](https://www.ruby-forum.com/u/unknown)\
**Post date:** [November 16, 2007, 3:54pm UTC](https://www.ruby-forum.com/t/railroad-problem/120399/3 "2007-11-16T15:54:40Z")

</div>

It looks like it is looking for a class called Pd and not PD.

Try “class Pd \< ActiveRecord::Base”.

On Fri, 16 Nov 2007 23:36:00 +0900, srinivasan.anand wrote