# Can't list db content in rails

**URL:** <https://www.ruby-forum.com/t/cant-list-db-content-in-rails/120492>\
**Category:** Rails\
**Created:** [November 17, 2007, 3:33pm UTC](https://www.ruby-forum.com/t/cant-list-db-content-in-rails/120492 "2007-11-17T15:33:58Z")\
**Posts on this page:** 7\
**Page:** 1

<div class="post-metadata">

**Author:** ![Edoardo\_Costa](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/e/a88e57/32.png) [@Edoardo\_Costa](https://www.ruby-forum.com/u/Edoardo_Costa)\
**Post date:** [November 17, 2007, 3:33pm UTC](https://www.ruby-forum.com/t/cant-list-db-content-in-rails/120492/1 "2007-11-17T15:33:58Z")

</div>

Hi all,  
I am very very new to ruby and rails so I thought I’d follow a couple of  
starter manuals.

Bellow the error I have listed versions and commands executed.

The problem I am having is that I can display:

[http://acc.precognet.com/invoices/new](http://acc.precognet.com/invoices/new)

but when I try to display:  
[http://acc.precognet.com/invoices](http://acc.precognet.com/invoices)  
or  
[http://acc.precognet.com/invoices/list](http://acc.precognet.com/invoices/list)

I get the following error:

NameError in InvoicesController#index  
uninitialized constant Invoice

RAILS\_ROOT: /var/www/acc.precognet.com/public/…/config/…  
Application Trace | Framework Trace | Full Trace  
/usr/lib/ruby/gems/1.8/gems/activesupport-1.4.4/lib/active\_support/dependencies.rb:266:in  
`load_missing_constant' /usr/lib/ruby/gems/1.8/gems/activesupport-1.4.4/lib/active_support/dependencies.rb:452:in `const\_missing’  
/usr/lib/ruby/gems/1.8/gems/activesupport-1.4.4/lib/active\_support/dependencies.rb:464:in  
`const_missing' /usr/lib/ruby/gems/1.8/gems/activesupport-1.4.4/lib/active_support/inflector.rb:250:in `constantize’  
/usr/lib/ruby/gems/1.8/gems/activesupport-1.4.4/lib/active\_support/core\_ext/string/inflections.rb:148:in  
`constantize' /usr/lib/ruby/gems/1.8/gems/actionpack-1.13.5/lib/action_controller/pagination.rb:201:in `paginator\_and\_collection\_for’  
/usr/lib/ruby/gems/1.8/gems/actionpack-1.13.5/lib/action\_controller/pagination.rb:132:in  
`paginate_without_deprecation' /usr/lib/ruby/gems/1.8/gems/activesupport-1.4.4/lib/active_support/deprecation.rb:94:in `paginate’  
/usr/lib/ruby/gems/1.8/gems/actionpack-1.13.5/lib/action\_controller/scaffolding.rb:108:in  
`list' /usr/lib/ruby/gems/1.8/gems/actionpack-1.13.5/lib/action_controller/scaffolding.rb:96:in `index’  
/usr/lib/ruby/gems/1.8/gems/actionpack-1.13.5/lib/action\_controller/base.rb:1101:in  
`send' /usr/lib/ruby/gems/1.8/gems/actionpack-1.13.5/lib/action_controller/base.rb:1101:in `perform\_action\_without\_filters’  
/usr/lib/ruby/gems/1.8/gems/actionpack-1.13.5/lib/action\_controller/filters.rb:696:in  
`call_filters' /usr/lib/ruby/gems/1.8/gems/actionpack-1.13.5/lib/action_controller/filters.rb:688:in `perform\_action\_without\_benchmark’  
/usr/lib/ruby/gems/1.8/gems/actionpack-1.13.5/lib/action\_controller/benchmarking.rb:66:in  
`perform_action_without_rescue' /usr/lib/ruby/1.8/benchmark.rb:293:in `measure’  
/usr/lib/ruby/gems/1.8/gems/actionpack-1.13.5/lib/action\_controller/benchmarking.rb:66:in  
`perform_action_without_rescue' /usr/lib/ruby/gems/1.8/gems/actionpack-1.13.5/lib/action_controller/rescue.rb:83:in `perform\_action’  
/usr/lib/ruby/gems/1.8/gems/actionpack-1.13.5/lib/action\_controller/base.rb:435:in  
`send' /usr/lib/ruby/gems/1.8/gems/actionpack-1.13.5/lib/action_controller/base.rb:435:in `process\_without\_filters’  
/usr/lib/ruby/gems/1.8/gems/actionpack-1.13.5/lib/action\_controller/filters.rb:684:in  
`process_without_session_management_support' /usr/lib/ruby/gems/1.8/gems/actionpack-1.13.5/lib/action_controller/session_management.rb:114:in `process’  
/usr/lib/ruby/gems/1.8/gems/actionpack-1.13.5/lib/action\_controller/base.rb:334:in  
`process' /usr/lib/ruby/gems/1.8/gems/rails-1.2.5/lib/dispatcher.rb:41:in `dispatch’  
/usr/lib/ruby/gems/1.8/gems/rails-1.2.5/lib/fcgi\_handler.rb:168:in  
`process_request' /usr/lib/ruby/gems/1.8/gems/rails-1.2.5/lib/fcgi_handler.rb:143:in `process\_each\_request!’  
/usr/lib/ruby/gems/1.8/gems/rails-1.2.5/lib/fcgi\_handler.rb:109:in  
`with_signal_handler' /usr/lib/ruby/gems/1.8/gems/rails-1.2.5/lib/fcgi_handler.rb:142:in `process\_each\_request!’  
/usr/lib/ruby/site\_ruby/1.8/fcgi.rb:600:in `each_cgi' /usr/lib/ruby/site_ruby/1.8/fcgi.rb:597:in `each’  
/usr/lib/ruby/site\_ruby/1.8/fcgi.rb:597:in `each_cgi' /usr/lib/ruby/gems/1.8/gems/rails-1.2.5/lib/fcgi_handler.rb:141:in `process\_each\_request!’  
/usr/lib/ruby/gems/1.8/gems/rails-1.2.5/lib/fcgi\_handler.rb:55:in  
`process!' /usr/lib/ruby/gems/1.8/gems/rails-1.2.5/lib/fcgi_handler.rb:25:in `process!’  
/var/www/acc.precognet.com/public/dispatch.fcgi:24  
Request

Parameters: {“invoices.html”=\>nil}

## Show session dump

flash: !map:ActionController::Flash::FlashHash {}

Response  
Headers: {“cookie”=\>[], “Cache-Control”=\>“no-cache”}

I am using:  
Ruby version 1.8.6 (i686-linux)  
RubyGems version 0.9.4  
Rails version 1.2.5  
Active Record version 1.15.5  
Action Pack version 1.13.5  
Action Web Service version 1.2.5  
Action Mailer version 1.3.5  
Active Support version 1.4.4  
Application root /var/www/acc.precognet.com  
Environment development  
Database adapter mysql

Here are all the steps I took:

# cd /var/www

# rails [acc.precognet.com](http://acc.precognet.com)

# cd [acc.precognet.com/config](http://acc.precognet.com/config)

dev info from database.yml  
development:  
adapter: mysql  
database: dev\_precognet  
username: dev  
password: password  
socket: /var/run/mysqld/mysqld.sock

I took an existing db, dumped it to an sql file, renamed the db to  
dev\_db and  
reinjected into mysql.

# cat /etc/apache2/vhosts.d/acc.precognet.com.conf

```
SetEnv RAILS_ENV development
        ServerName acc.precognet.com
        DocumentRoot /var/www/acc.precognet.com/public
        ServerSignature On
        ErrorDocument 500 /500.html
        ErrorLog /var/log/apache2/acc.precognet.com.error_log
        CustomLog /var/log/apache2/acc.precognet.com.access_log combined
        LogLevel warn
        
                Options ExecCGI FollowSymLinks
                AddHandler fcgid-script .fcgi
                Order allow,deny
                Allow from all
                RewriteEngine On
                RewriteRule ^$ index.html [QSA]
                RewriteRule ^([^.]+)$ $1.html [QSA]
                RewriteCond %{REQUEST_FILENAME} !-f
                RewriteRule ^(.*)$ /dispatch.fcgi?$1 [QSA,L]
                AllowOverride None
```

# /etc/init.d/apache2 restart

# cd /var/www/acc.precognet.com

# ruby script/generate model invoices

# ruby script/generate controler invoices

# cat app/controllers/invoices\_controller.rb

class InvoicesController \< ApplicationController  
scaffold :invoices  
end

# chown -R apache:apache public tmp

# vi public/dispatch.fcgi

RailsFCGIHandler.process!  
‘/var/log/apache2/acc.precognet.com\_fcgi\_crash.log’

# touch /var/log/apache2/acc.precognet.com\_fcgi\_crash.log

# chown apache:apache /var/log/apache2/acc.precognet.com\_fcgi\_crash.log

Replace the following in public/.htaccess  
#RewriteRule ^(._)$ dispatch.cgi [QSA,L]  
RewriteRule ^(._)$ dispatch.fcgi [QSA,L]

## Relevant SQL table dump:

## – Table structure for table `invoices`

DROP TABLE IF EXISTS `invoices`;  
CREATE TABLE `invoices` (  
`id` int(6) unsigned zerofill NOT NULL,  
`cli_id` int(8) unsigned zerofill NOT NULL,  
`sent` date NOT NULL,  
`amount` decimal(7,2) NOT NULL,  
`payed` date default NULL,  
`path` varchar(254) default NULL,  
`filename` varchar(15) default NULL,  
PRIMARY KEY (`id`)  
) ENGINE=MyISAM AUTO\_INCREMENT=6 DEFAULT CHARSET=utf8 COMMENT=‘Precognet  
invoices table’;

I’m sorry for the long post but I have tried many times and never get  
past  
this step.

I hope someone can help 🙂  
-Ed

* * *

---

<div class="post-metadata">

**Author:** ![Edoardo\_Costa](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/e/a88e57/32.png) [@Edoardo\_Costa](https://www.ruby-forum.com/u/Edoardo_Costa)\
**Post date:** [November 18, 2007, 12:58am UTC](https://www.ruby-forum.com/t/cant-list-db-content-in-rails/120492/2 "2007-11-18T00:58:22Z")

</div>

The following is something I have discovered although I can’t figure  
out why…

My tables tend to end with an ‘s’ such as clients but if I run the  
following commands without the ‘s’ (single client) , then it works

# ruby script/generate model client

```
  exists app/models/
  exists test/unit/
  exists test/fixtures/
  create app/models/client.rb
  create test/unit/client_test.rb
  create test/fixtures/clients.yml
  create db/migrate
  create db/migrate/001_create_clients.rb

```

# ruby script/generate controler client

```
  exists app/controllers/
  exists app/helpers/
  create app/views/client
  exists test/functional/
  create app/controllers/client_controller.rb
  create test/functional/client_controller_test.rb
  create app/helpers/client_helper.rb

```

[http://acc.precognet.com/client](http://acc.precognet.com/client)  
Listing clients  
…

So even though I mention the wrong table name ‘client’ rather than  
‘clients’, it works and the output says ‘clients’!!

Any thoughts on this?  
-Ed

---

<div class="post-metadata">

**Author:** ![Edoardo\_Costa](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/e/a88e57/32.png) [@Edoardo\_Costa](https://www.ruby-forum.com/u/Edoardo_Costa)\
**Post date:** [November 18, 2007, 5:37am UTC](https://www.ruby-forum.com/t/cant-list-db-content-in-rails/120492/3 "2007-11-18T05:37:11Z")

</div>

Hi Ed

Using Active Scaffold makes data manipulation and display pretty  
trival.

CCH

> **[Rails... Rails... Rails](http://cch4rails.blogspot.com)**
>
> Chee Chong Hwa aka CCH, a Malaysian Chief Software Architect blogs on his experiences with Ruby on Rail running on Win2003 Server+Apache 2.26 environment since 2007. Flirted briefly with Ubuntu 9.04 in 2009. Since January 2017, now using RubyMine...

---

<div class="post-metadata">

**Author:** ![Edoardo\_Costa](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/e/a88e57/32.png) [@Edoardo\_Costa](https://www.ruby-forum.com/u/Edoardo_Costa)\
**Post date:** [November 18, 2007, 10:43am UTC](https://www.ruby-forum.com/t/cant-list-db-content-in-rails/120492/4 "2007-11-18T10:43:20Z")

</div>

Hi CCH

On Nov 18, 4:53 pm, “removed\_email\_address@domain.invalid”  
[removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote:

> Hi CCH,  
> Could you be a bit more specific?

cch : What I meant was database web development is a breeze with  
Active Scaffold plugin installed.

> model and build using the client succeeds
> 
> Now I doubt very much that a requirement of rails is that all tables  
> should end with an ‘s’ and all reference to them should ‘lose’ the  
> ‘s’… so what am I doing wrong?

cch: Yes, it is a Rails convention that all tables should end with an  
‘s’ unless you turn pluralization off.

CCH

> **[Rails... Rails... Rails](http://cch4rails.blogspot.com)**
>
> Chee Chong Hwa aka CCH, a Malaysian Chief Software Architect blogs on his experiences with Ruby on Rail running on Win2003 Server+Apache 2.26 environment since 2007. Flirted briefly with Ubuntu 9.04 in 2009. Since January 2017, now using RubyMine...

---

<div class="post-metadata">

**Author:** ![Edoardo\_Costa](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/e/a88e57/32.png) [@Edoardo\_Costa](https://www.ruby-forum.com/u/Edoardo_Costa)\
**Post date:** [November 18, 2007, 9:54am UTC](https://www.ruby-forum.com/t/cant-list-db-content-in-rails/120492/5 "2007-11-18T09:54:14Z")

</div>

Hi CCH,  
Could you be a bit more specific?

The problem I had was for example:

1. table named clients  
model and build using the client_s_ fails

2. table named client  
model and build using the client fails

3. table named clients  
model and build using the client succeeds

Now I doubt very much that a requirement of rails is that all tables  
should end with an ‘s’ and all reference to them should ‘lose’ the  
‘s’… so what am I doing wrong?  
-Ed

---

<div class="post-metadata">

**Author:** ![Edoardo\_Costa](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/e/a88e57/32.png) [@Edoardo\_Costa](https://www.ruby-forum.com/u/Edoardo_Costa)\
**Post date:** [November 18, 2007, 12:09pm UTC](https://www.ruby-forum.com/t/cant-list-db-content-in-rails/120492/6 "2007-11-18T12:09:56Z")

</div>

On Nov 18, 10:42 am, CCH [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote:  
…

> cch: Yes, it is a Rails convention that all tables should end with an  
> ‘s’ unless you turn pluralization off.
> 
> CCHhttp://cch4rails.blogspot.com

Hmmm, yes, just read about that. Odd but I guess taht with time I’ll  
understand why.

Thanks for your input, I am one step further in the learning curve 🙂  
-Ed

---

<div class="post-metadata">

**Author:** ![Edoardo\_Costa](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/e/a88e57/32.png) [@Edoardo\_Costa](https://www.ruby-forum.com/u/Edoardo_Costa)\
**Post date:** [November 18, 2007, 6:52pm UTC](https://www.ruby-forum.com/t/cant-list-db-content-in-rails/120492/7 "2007-11-18T18:52:31Z")

</div>

Well, thats not completely true. Tables should be plural (but not  
necessarily with an s) and your models should be singular. It’s just a  
conventions so that rails knows what table to look for, plus it makes  
sense. Take the example of a table holding people’s information. The  
table would be called people and the model would be person. This makes  
sense since because there are multiple people in the table so the  
table’s name rightly is “people”. When you pull a record from that  
table and instantiate an object of your Person class, the singular name  
“Person” then makes sense because it represents one person from a table  
of people.

Hope this clears it up a bit,  
-Bill