Rails - Jan 2006 - error when adding a new table to the existing application

Deniz wrote:
> Hi Everybody,
> I am a newbie in this list so please forgive me if this is a lengthy 
> message.
> Currently I am working on a project at my work place that includes 
> viewing some oracle tables(I do not have control over to rewrite the 
> tables) and searching the tables based on a given criteria with Rails. 
> Up untill now everything was working great. The database consists of a 
> lot of tables but I was working with five of them. Then I realized 
> that one of the fields in a table was referring to another table in 
> the database. For example if I had a DN (Directory Number) in the 
> table, that three digit DN was referring to another table being an 
> actual DN. So I decided to add that table. The actual name of the 
> table is cfg_dn (Legacy) with the following assignments I created the 
> model/controller and view
>
> */ruby script/generate scaffold cfg_dn cfg_dn
>
> /*Again, up untill now everything that I wanted to do with the 
> database was working properly. I went ahead and typed the following to 
> my browser to see if I am hitting the table.
>
> /*http://localhost:3000/cfg_dn*/
>
> To my amazement the error I got:
>
>
>   NoMethodError in Cfg_dn#index
>
>undefined method `empty?'' for 3:Fixnum
>
> |RAILS_ROOT: ./script/../config/..|
>
> Application Trace <http://localhost:3000/cfg_dn#> | Framework Trace 
> <http://localhost:3000/cfg_dn#> | Full Trace 
> <http://localhost:3000/cfg_dn#>
>
>|c:/ruby/lib/ruby/gems/1.8/gems/activerecord-1.13.2/lib/active_record/base.rb:890:in
`instantiate_without_callbacks''
>c:/ruby/lib/ruby/gems/1.8/gems/activerecord-1.13.2/lib/active_record/callbacks.rb:215:in
`instantiate''
>c:/ruby/lib/ruby/gems/1.8/gems/activerecord-1.13.2/lib/active_record/base.rb:431:in
`find_by_sql''
>c:/ruby/lib/ruby/gems/1.8/gems/activerecord-1.13.2/lib/active_record/base.rb:431:in
`collect!''
>c:/ruby/lib/ruby/gems/1.8/gems/activerecord-1.13.2/lib/active_record/base.rb:431:in
`find_by_sql''
>c:/ruby/lib/ruby/gems/1.8/gems/activerecord-1.13.2/lib/active_record/base.rb:395:in
`find''
>c:/ruby/lib/ruby/gems/1.8/gems/actionpack-1.11.2/lib/action_controller/pagination.rb:174:in
`find_collection_for_pagination''
>c:/ruby/lib/ruby/gems/1.8/gems/actionpack-1.11.2/lib/action_controller/pagination.rb:192:in
`paginator_and_collection_for''
>c:/ruby/lib/ruby/gems/1.8/gems/actionpack-1.11.2/lib/action_controller/pagination.rb:124:in
`paginate''
>#{RAILS_ROOT}/app/controllers/cfg_dn_controller.rb:8:in `list''
>#{RAILS_ROOT}/app/controllers/cfg_dn_controller.rb:3:in `index''|
>
>|c:/ruby/lib/ruby/gems/1.8/gems/activerecord-1.13.2/lib/active_record/base.rb:890:in
`instantiate_without_callbacks''
>c:/ruby/lib/ruby/gems/1.8/gems/activerecord-1.13.2/lib/active_record/callbacks.rb:215:in
`instantiate''
>c:/ruby/lib/ruby/gems/1.8/gems/activerecord-1.13.2/lib/active_record/base.rb:431:in
`find_by_sql''
>c:/ruby/lib/ruby/gems/1.8/gems/activerecord-1.13.2/lib/active_record/base.rb:431:in
`collect!''
>c:/ruby/lib/ruby/gems/1.8/gems/activerecord-1.13.2/lib/active_record/base.rb:431:in
`find_by_sql''
>c:/ruby/lib/ruby/gems/1.8/gems/activerecord-1.13.2/lib/active_record/base.rb:395:in
`find''
>c:/ruby/lib/ruby/gems/1.8/gems/actionpack-1.11.2/lib/action_controller/pagination.rb:174:in
`find_collection_for_pagination''
>c:/ruby/lib/ruby/gems/1.8/gems/actionpack-1.11.2/lib/action_controller/pagination.rb:192:in
`paginator_and_collection_for''
>c:/ruby/lib/ruby/gems/1.8/gems/actionpack-1.11.2/lib/action_controller/pagination.rb:124:in
`paginate''
>c:/ruby/lib/ruby/gems/1.8/gems/actionpack-1.11.2/lib/action_controller/base.rb:853:in
`send''
>c:/ruby/lib/ruby/gems/1.8/gems/actionpack-1.11.2/lib/action_controller/base.rb:853:in
`perform_action_without_filters''
>c:/ruby/lib/ruby/gems/1.8/gems/actionpack-1.11.2/lib/action_controller/filters.rb:332:in
`perform_action_without_benchmark''
>c:/ruby/lib/ruby/gems/1.8/gems/actionpack-1.11.2/lib/action_controller/benchmarking.rb:69:in
`perform_action_without_rescue''
>c:/ruby/lib/ruby/gems/1.8/gems/actionpack-1.11.2/lib/action_controller/benchmarking.rb:69:in
`measure''
>c:/ruby/lib/ruby/gems/1.8/gems/actionpack-1.11.2/lib/action_controller/benchmarking.rb:69:in
`perform_action_without_rescue''
>c:/ruby/lib/ruby/gems/1.8/gems/actionpack-1.11.2/lib/action_controller/rescue.rb:82:in
`perform_action''
>c:/ruby/lib/ruby/gems/1.8/gems/actionpack-1.11.2/lib/action_controller/base.rb:369:in
`send''
>c:/ruby/lib/ruby/gems/1.8/gems/actionpack-1.11.2/lib/action_controller/base.rb:369:in
`process_without_session_management_support''
>c:/ruby/lib/ruby/gems/1.8/gems/actionpack-1.11.2/lib/action_controller/session_management.rb:116:in
`process''
>c:/ruby/lib/ruby/gems/1.8/gems/rails-1.0.0/lib/dispatcher.rb:38:in
`dispatch''
>c:/ruby/lib/ruby/gems/1.8/gems/rails-1.0.0/lib/webrick_server.rb:117:in
`handle_dispatch''
>c:/ruby/lib/ruby/gems/1.8/gems/rails-1.0.0/lib/webrick_server.rb:83:in
`service''
>c:/ruby/lib/ruby/1.8/webrick/httpserver.rb:104:in `service''
>c:/ruby/lib/ruby/1.8/webrick/httpserver.rb:65:in `run''
>c:/ruby/lib/ruby/1.8/webrick/server.rb:155:in `start_thread''
>c:/ruby/lib/ruby/1.8/webrick/server.rb:144:in `start''
>c:/ruby/lib/ruby/1.8/webrick/server.rb:144:in `start_thread''
>c:/ruby/lib/ruby/1.8/webrick/server.rb:94:in `start''
>c:/ruby/lib/ruby/1.8/webrick/server.rb:89:in `each''
>c:/ruby/lib/ruby/1.8/webrick/server.rb:89:in `start''
>c:/ruby/lib/ruby/1.8/webrick/server.rb:79:in `start''
>c:/ruby/lib/ruby/1.8/webrick/server.rb:79:in `start''
>c:/ruby/lib/ruby/gems/1.8/gems/rails-1.0.0/lib/webrick_server.rb:69:in
`dispatch''
>c:/ruby/lib/ruby/gems/1.8/gems/rails-1.0.0/lib/commands/servers/webrick.rb:59
>c:/ruby/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:18:in
`require__''
>c:/ruby/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:18:in
`require''
>c:/ruby/lib/ruby/gems/1.8/gems/activesupport-1.2.5/lib/active_support/dependencies.rb:214:in
`require''
>c:/ruby/lib/ruby/gems/1.8/gems/rails-1.0.0/lib/commands/server.rb:28
>c:/ruby/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:18:in
`require__''
>c:/ruby/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:18:in
`require''
>c:/ruby/lib/ruby/gems/1.8/gems/activesupport-1.2.5/lib/active_support/dependencies.rb:214:in
`require''
>script/server:5|
>
>|c:/ruby/lib/ruby/gems/1.8/gems/activerecord-1.13.2/lib/active_record/base.rb:890:in
`instantiate_without_callbacks''
>c:/ruby/lib/ruby/gems/1.8/gems/activerecord-1.13.2/lib/active_record/callbacks.rb:215:in
`instantiate''
>c:/ruby/lib/ruby/gems/1.8/gems/activerecord-1.13.2/lib/active_record/base.rb:431:in
`find_by_sql''
>c:/ruby/lib/ruby/gems/1.8/gems/activerecord-1.13.2/lib/active_record/base.rb:431:in
`collect!''
>c:/ruby/lib/ruby/gems/1.8/gems/activerecord-1.13.2/lib/active_record/base.rb:431:in
`find_by_sql''
>c:/ruby/lib/ruby/gems/1.8/gems/activerecord-1.13.2/lib/active_record/base.rb:395:in
`find''
>c:/ruby/lib/ruby/gems/1.8/gems/actionpack-1.11.2/lib/action_controller/pagination.rb:174:in
`find_collection_for_pagination''
>c:/ruby/lib/ruby/gems/1.8/gems/actionpack-1.11.2/lib/action_controller/pagination.rb:192:in
`paginator_and_collection_for''
>c:/ruby/lib/ruby/gems/1.8/gems/actionpack-1.11.2/lib/action_controller/pagination.rb:124:in
`paginate''
>#{RAILS_ROOT}/app/controllers/cfg_dn_controller.rb:8:in `list''
>#{RAILS_ROOT}/app/controllers/cfg_dn_controller.rb:3:in `index''
>c:/ruby/lib/ruby/gems/1.8/gems/actionpack-1.11.2/lib/action_controller/base.rb:853:in
`send''
>c:/ruby/lib/ruby/gems/1.8/gems/actionpack-1.11.2/lib/action_controller/base.rb:853:in
`perform_action_without_filters''
>c:/ruby/lib/ruby/gems/1.8/gems/actionpack-1.11.2/lib/action_controller/filters.rb:332:in
`perform_action_without_benchmark''
>c:/ruby/lib/ruby/gems/1.8/gems/actionpack-1.11.2/lib/action_controller/benchmarking.rb:69:in
`perform_action_without_rescue''
>c:/ruby/lib/ruby/gems/1.8/gems/actionpack-1.11.2/lib/action_controller/benchmarking.rb:69:in
`measure''
>c:/ruby/lib/ruby/gems/1.8/gems/actionpack-1.11.2/lib/action_controller/benchmarking.rb:69:in
`perform_action_without_rescue''
>c:/ruby/lib/ruby/gems/1.8/gems/actionpack-1.11.2/lib/action_controller/rescue.rb:82:in
`perform_action''
>c:/ruby/lib/ruby/gems/1.8/gems/actionpack-1.11.2/lib/action_controller/base.rb:369:in
`send''
>c:/ruby/lib/ruby/gems/1.8/gems/actionpack-1.11.2/lib/action_controller/base.rb:369:in
`process_without_session_management_support''
>c:/ruby/lib/ruby/gems/1.8/gems/actionpack-1.11.2/lib/action_controller/session_management.rb:116:in
`process''
>c:/ruby/lib/ruby/gems/1.8/gems/rails-1.0.0/lib/dispatcher.rb:38:in
`dispatch''
>c:/ruby/lib/ruby/gems/1.8/gems/rails-1.0.0/lib/webrick_server.rb:117:in
`handle_dispatch''
>c:/ruby/lib/ruby/gems/1.8/gems/rails-1.0.0/lib/webrick_server.rb:83:in
`service''
>c:/ruby/lib/ruby/1.8/webrick/httpserver.rb:104:in `service''
>c:/ruby/lib/ruby/1.8/webrick/httpserver.rb:65:in `run''
>c:/ruby/lib/ruby/1.8/webrick/server.rb:155:in `start_thread''
>c:/ruby/lib/ruby/1.8/webrick/server.rb:144:in `start''
>c:/ruby/lib/ruby/1.8/webrick/server.rb:144:in `start_thread''
>c:/ruby/lib/ruby/1.8/webrick/server.rb:94:in `start''
>c:/ruby/lib/ruby/1.8/webrick/server.rb:89:in `each''
>c:/ruby/lib/ruby/1.8/webrick/server.rb:89:in `start''
>c:/ruby/lib/ruby/1.8/webrick/server.rb:79:in `start''
>c:/ruby/lib/ruby/1.8/webrick/server.rb:79:in `start''
>c:/ruby/lib/ruby/gems/1.8/gems/rails-1.0.0/lib/webrick_server.rb:69:in
`dispatch''
>c:/ruby/lib/ruby/gems/1.8/gems/rails-1.0.0/lib/commands/servers/webrick.rb:59
>c:/ruby/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:18:in
`require__''
>c:/ruby/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:18:in
`require''
>c:/ruby/lib/ruby/gems/1.8/gems/activesupport-1.2.5/lib/active_support/dependencies.rb:214:in
`require''
>c:/ruby/lib/ruby/gems/1.8/gems/rails-1.0.0/lib/commands/server.rb:28
>c:/ruby/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:18:in
`require__''
>c:/ruby/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:18:in
`require''
>c:/ruby/lib/ruby/gems/1.8/gems/activesupport-1.2.5/lib/active_support/dependencies.rb:214:in
`require''
>script/server:5|
>
>
>     Request
>
> *Parameters*: None
>
> Show session dump <http://localhost:3000/cfg_dn#>
>
>--- 
>flash: !ruby/hash:ActionController::Flash::FlashHash {}
>
>
>     Response
>
> *Headers*: {"cookie"=>[],
"Cache-Control"=>"no-cache"}
>
> Also please note that when i do the same thing for the previous five 
> tables, it works. It is just this table that I am having problem with. 
> And another thing is that I am able to see this table using Brio 
> Software (This software allows you to put together tables and do some 
> queries on it). So the table is definetely there and the contents are 
> definetely there.
> I do not know what this error means and I do not know how to fix it. 
> Could any one give me some suggestions?
> I would be more than happy to give more information if necessary.
> Thanks a lot
> Deniz Rende.
>
>------------------------------------------------------------------------
>
>_______________________________________________
>Rails mailing list
>Rails@lists.rubyonrails.org
>http://lists.rubyonrails.org/mailman/listinfo/rails
>  
>
Could anybody give me more suggestions on this problem please? I''ve
been
constantly trying to figure out for almost 2 weeks.
Please let me know if you guys need more feedback...
Thank you very much
Dnz...


-------------- next part --------------
An HTML attachment was scrubbed...
URL:
http://wrath.rubyonrails.org/pipermail/rails/attachments/20060130/03ec09be/attachment.html

Deniz wrote:
>   Deniz wrote:
>> Hi Everybody,
>> I am a newbie in this list so please forgive me if this is a lengthy 
>> message.
<snip>

What''s the schema?

-- 
Alex

Alex Young wrote:
> Deniz wrote:
>
>>   Deniz wrote:
>>
>>> Hi Everybody,
>>> I am a newbie in this list so please forgive me if this is a
lengthy
>>> message.
>>
> <snip>
>
> What''s the schema?
>
It connects to a remote oracle database through vpn..

Deniz wrote:
> Alex Young wrote:
>> <snip>
>>
>> What''s the schema?
>>
> It connects to a remote oracle database through vpn..
Right.  So what''s the schema?  What''s the table definition for
cfg_dn?

-- 
Alex

Alex Young wrote:
> Deniz wrote:
>
>> Alex Young wrote:
>>
>>> <snip>
>>>
>>> What''s the schema?
>>>
>> It connects to a remote oracle database through vpn..
>
> Right.  So what''s the schema?  What''s the table
definition for cfg_dn?
>
Okey,
Sorry about that, Below is the table def for cfg_dn
DBID [DECIMAL(10,0), Required]
SWITCH_DBID[DECIMAL(10,0), Nullable]
TENANT_DBID[DECIMAL(10,0), Nullable]
TYPE [DECIMAL(38,0), Nullable]
NUMBER_ [VARCHAR2(255),Nullable]
ASSOCIATION [VARCHAR2(255),Nullable]
LOGIN_FLAG [DECIMAL(38,0),Nullable]
DN_LOGIN_ID [VARCHAR2(255),Nullable]
REGISTER_ALL [DECIMAL(38,0), Nullable]
GROUP_DBID[DECIMAL(10,0), Nullable]
TRUNKS [DECIMAL(10,0), Nullable]
ROUTE_TYPE[DECIMAL(38,0), Nullable]
OVERRIDE [VARCHAR2(255),Nullable]
STATE [DECIMAL(38,0), Nullable]
NAME [VARCHAR2(255),Nullable]
USE-OVERRIDE[DECIMAL[38,0],Nullable]
SW_SPECIFIC_TYPE [DECIMAL[38,0],Nullable]
CSID [DECIMAL(10,0), Nullable]
SWITCH_CSID [DECIMAL(10,0), Nullable]
TENANT_CSID [DECIMAL(10,0), Nullable]
GROUP_CSID[DECIMAL(10,0), Nullable]
PLACE_DBID[DECIMAL(10,0), Nullable]
PLACE_CSID[DECIMAL(10,0), Nullable]
<End of List>

As I mentioned before, I am not authorized to overide the tables. I 
obtained the list using MSQUERY32.exe
Thanks..
Dnz

Deniz wrote:
> Alex Young wrote:
> 
>> Deniz wrote:
>>
>>> Alex Young wrote:
>>>
>>>> <snip>
>>>>
>>>> What''s the schema?
>>>>
>>> It connects to a remote oracle database through vpn..
>>
>> Right.  So what''s the schema?  What''s the table
definition for cfg_dn?
>>
Got it.  I think it''s your TYPE column.  ActiveRecord uses `type` as an
indicator for single table inheritance, and the code assumes the 
content''s going to be a string, which is why it''s calling a
string
method on it.  Nasty little bug you''ve found there, and I can entirely 
see why it''s been confusing.  It''s funny, though - the MySQL
adapter
distinguishes between `TYPE` and `type`, and gives a different error to 
the one you''ve sent when the lower-case value is used.  I can only 
assume that the Oracle adapter for some reason allows that not to get 
caught...

Try changing your app/models/cfg_dn.rb to look something like this:

class CfgDn < ActiveRecord::Base
   def self.inheritance_column()
     ''dontcare''
   end
end

I haven''t tested it, but the inheritance_column() method should tell it
to look for a column named ''dontcare'' when determining whether
or not to
trigger single table inheritance.  That column doesn''t exist, so the 
failing method shouldn''t get triggered.

If it turns out not to be that, I reckon it''s got to be data-dependent.
  I would suggest trying out the scaffolding on an empty database with 
the same schema, and slowly add data in until you get it to fail...

Hope this helps,
-- 
Alex

Alex Young wrote:
> Deniz wrote:
>
>> Alex Young wrote:
>>
>>> Deniz wrote:
>>>
>>>> Alex Young wrote:
>>>>
>>>>> <snip>
>>>>>
>>>>> What''s the schema?
>>>>>
>>>> It connects to a remote oracle database through vpn..
>>>
>>>
>>> Right.  So what''s the schema?  What''s the table
definition for cfg_dn?
>>>
> Got it.  I think it''s your TYPE column.  ActiveRecord uses `type`
as
> an indicator for single table inheritance, and the code assumes the 
> content''s going to be a string, which is why it''s calling
a string
> method on it.  Nasty little bug you''ve found there, and I can
entirely
> see why it''s been confusing.  It''s funny, though - the
MySQL adapter
> distinguishes between `TYPE` and `type`, and gives a different error 
> to the one you''ve sent when the lower-case value is used.  I can
only
> assume that the Oracle adapter for some reason allows that not to get 
> caught...
>
> Try changing your app/models/cfg_dn.rb to look something like this:
>
> class CfgDn < ActiveRecord::Base
>   def self.inheritance_column()
>     ''dontcare''
>   end
> end
>
> I haven''t tested it, but the inheritance_column() method should
tell
> it to look for a column named ''dontcare'' when determining
whether or
> not to trigger single table inheritance.  That column doesn''t
exist,
> so the failing method shouldn''t get triggered.
>
> If it turns out not to be that, I reckon it''s got to be 
> data-dependent.  I would suggest trying out the scaffolding on an 
> empty database with the same schema, and slowly add data in until you 
> get it to fail...
>
> Hope this helps,
Alex,
You are absolutely awsome. Thank you very much. It worked and I don''t 
know how and why. I looked at your explanation and I changed the model 
as you suggested. At first I put ''Number'' in the place of
''dontcare'' and
as a result I got the following error:


  ActiveRecord::SubclassNotFound in Test#index

The single-table inheritance mechanism failed to locate the subclass:
''Q410''. This error is raised because the column
''number_'' is reserved for storing the class in case of
inheritance. Please rename this column if you didn''t intend it to be
used for storing the inheritance class or overwrite CfgDn.inheritance_column to
use another column for that information.

|RAILS_ROOT: ./script/../config/..|

Application Trace <http://localhost:3000/test#> | Framework Trace 
<http://localhost:3000/test#> | Full Trace
<http://localhost:3000/test#>

|c:/ruby/lib/ruby/gems/1.8/gems/activerecord-1.13.2/lib/active_record/base.rb:897:in
`instantiate_without_callbacks''
c:/ruby/lib/ruby/gems/1.8/gems/activerecord-1.13.2/lib/active_record/callbacks.rb:215:in
`instantiate''
c:/ruby/lib/ruby/gems/1.8/gems/activerecord-1.13.2/lib/active_record/base.rb:431:in
`find_by_sql''
c:/ruby/lib/ruby/gems/1.8/gems/activerecord-1.13.2/lib/active_record/base.rb:431:in
`find_by_sql''
c:/ruby/lib/ruby/gems/1.8/gems/activerecord-1.13.2/lib/active_record/base.rb:395:in
`find''
c:/ruby/lib/ruby/gems/1.8/gems/actionpack-1.11.2/lib/action_controller/pagination.rb:174:in
`find_collection_for_pagination''
c:/ruby/lib/ruby/gems/1.8/gems/actionpack-1.11.2/lib/action_controller/pagination.rb:192:in
`paginator_and_collection_for''
c:/ruby/lib/ruby/gems/1.8/gems/actionpack-1.11.2/lib/action_controller/pagination.rb:124:in
`paginate''
#{RAILS_ROOT}/app/controllers/test_controller.rb:8:in `list''
#{RAILS_ROOT}/app/controllers/test_controller.rb:3:in `index''|

|c:/ruby/lib/ruby/gems/1.8/gems/activerecord-1.13.2/lib/active_record/base.rb:897:in
`instantiate_without_callbacks''
c:/ruby/lib/ruby/gems/1.8/gems/activerecord-1.13.2/lib/active_record/callbacks.rb:215:in
`instantiate''
c:/ruby/lib/ruby/gems/1.8/gems/activerecord-1.13.2/lib/active_record/base.rb:431:in
`find_by_sql''
c:/ruby/lib/ruby/gems/1.8/gems/activerecord-1.13.2/lib/active_record/base.rb:431:in
`find_by_sql''
c:/ruby/lib/ruby/gems/1.8/gems/activerecord-1.13.2/lib/active_record/base.rb:395:in
`find''
c:/ruby/lib/ruby/gems/1.8/gems/actionpack-1.11.2/lib/action_controller/pagination.rb:174:in
`find_collection_for_pagination''
c:/ruby/lib/ruby/gems/1.8/gems/actionpack-1.11.2/lib/action_controller/pagination.rb:192:in
`paginator_and_collection_for''
c:/ruby/lib/ruby/gems/1.8/gems/actionpack-1.11.2/lib/action_controller/pagination.rb:124:in
`paginate''
c:/ruby/lib/ruby/gems/1.8/gems/actionpack-1.11.2/lib/action_controller/base.rb:853:in
`perform_action_without_filters''
c:/ruby/lib/ruby/gems/1.8/gems/actionpack-1.11.2/lib/action_controller/filters.rb:332:in
`perform_action_without_benchmark''
c:/ruby/lib/ruby/gems/1.8/gems/actionpack-1.11.2/lib/action_controller/benchmarking.rb:69:in
`perform_action_without_rescue''
c:/ruby/lib/ruby/1.8/benchmark.rb:293:in `measure''
c:/ruby/lib/ruby/gems/1.8/gems/actionpack-1.11.2/lib/action_controller/benchmarking.rb:69:in
`perform_action_without_rescue''
c:/ruby/lib/ruby/gems/1.8/gems/actionpack-1.11.2/lib/action_controller/rescue.rb:82:in
`perform_action''
c:/ruby/lib/ruby/gems/1.8/gems/actionpack-1.11.2/lib/action_controller/base.rb:369:in
`process_without_session_management_support''
c:/ruby/lib/ruby/gems/1.8/gems/actionpack-1.11.2/lib/action_controller/session_management.rb:116:in
`process''
c:/ruby/lib/ruby/gems/1.8/gems/rails-1.0.0/lib/dispatcher.rb:38:in
`dispatch''
c:/ruby/lib/ruby/gems/1.8/gems/rails-1.0.0/lib/webrick_server.rb:117:in
`handle_dispatch''
c:/ruby/lib/ruby/gems/1.8/gems/rails-1.0.0/lib/webrick_server.rb:83:in
`service''
c:/ruby/lib/ruby/1.8/webrick/httpserver.rb:104:in `service''
c:/ruby/lib/ruby/1.8/webrick/httpserver.rb:65:in `run''
c:/ruby/lib/ruby/1.8/webrick/server.rb:173:in `start_thread''
c:/ruby/lib/ruby/1.8/webrick/server.rb:162:in `start_thread''
c:/ruby/lib/ruby/1.8/webrick/server.rb:95:in `start''
c:/ruby/lib/ruby/1.8/webrick/server.rb:92:in `start''
c:/ruby/lib/ruby/1.8/webrick/server.rb:23:in `start''
c:/ruby/lib/ruby/1.8/webrick/server.rb:82:in `start''
c:/ruby/lib/ruby/gems/1.8/gems/rails-1.0.0/lib/webrick_server.rb:69:in
`dispatch''
c:/ruby/lib/ruby/gems/1.8/gems/rails-1.0.0/lib/commands/servers/webrick.rb:59
c:/ruby/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:21:in
`require''
c:/ruby/lib/ruby/gems/1.8/gems/activesupport-1.2.5/lib/active_support/dependencies.rb:214:in
`require''
c:/ruby/lib/ruby/gems/1.8/gems/rails-1.0.0/lib/commands/server.rb:28
c:/ruby/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:21:in
`require''
c:/ruby/lib/ruby/gems/1.8/gems/activesupport-1.2.5/lib/active_support/dependencies.rb:214:in
`require''
script/server:5|

|c:/ruby/lib/ruby/gems/1.8/gems/activerecord-1.13.2/lib/active_record/base.rb:897:in
`instantiate_without_callbacks''
c:/ruby/lib/ruby/gems/1.8/gems/activerecord-1.13.2/lib/active_record/callbacks.rb:215:in
`instantiate''
c:/ruby/lib/ruby/gems/1.8/gems/activerecord-1.13.2/lib/active_record/base.rb:431:in
`find_by_sql''
c:/ruby/lib/ruby/gems/1.8/gems/activerecord-1.13.2/lib/active_record/base.rb:431:in
`find_by_sql''
c:/ruby/lib/ruby/gems/1.8/gems/activerecord-1.13.2/lib/active_record/base.rb:395:in
`find''
c:/ruby/lib/ruby/gems/1.8/gems/actionpack-1.11.2/lib/action_controller/pagination.rb:174:in
`find_collection_for_pagination''
c:/ruby/lib/ruby/gems/1.8/gems/actionpack-1.11.2/lib/action_controller/pagination.rb:192:in
`paginator_and_collection_for''
c:/ruby/lib/ruby/gems/1.8/gems/actionpack-1.11.2/lib/action_controller/pagination.rb:124:in
`paginate''
#{RAILS_ROOT}/app/controllers/test_controller.rb:8:in `list''
#{RAILS_ROOT}/app/controllers/test_controller.rb:3:in `index''
c:/ruby/lib/ruby/gems/1.8/gems/actionpack-1.11.2/lib/action_controller/base.rb:853:in
`perform_action_without_filters''
c:/ruby/lib/ruby/gems/1.8/gems/actionpack-1.11.2/lib/action_controller/filters.rb:332:in
`perform_action_without_benchmark''
c:/ruby/lib/ruby/gems/1.8/gems/actionpack-1.11.2/lib/action_controller/benchmarking.rb:69:in
`perform_action_without_rescue''
c:/ruby/lib/ruby/1.8/benchmark.rb:293:in `measure''
c:/ruby/lib/ruby/gems/1.8/gems/actionpack-1.11.2/lib/action_controller/benchmarking.rb:69:in
`perform_action_without_rescue''
c:/ruby/lib/ruby/gems/1.8/gems/actionpack-1.11.2/lib/action_controller/rescue.rb:82:in
`perform_action''
c:/ruby/lib/ruby/gems/1.8/gems/actionpack-1.11.2/lib/action_controller/base.rb:369:in
`process_without_session_management_support''
c:/ruby/lib/ruby/gems/1.8/gems/actionpack-1.11.2/lib/action_controller/session_management.rb:116:in
`process''
c:/ruby/lib/ruby/gems/1.8/gems/rails-1.0.0/lib/dispatcher.rb:38:in
`dispatch''
c:/ruby/lib/ruby/gems/1.8/gems/rails-1.0.0/lib/webrick_server.rb:117:in
`handle_dispatch''
c:/ruby/lib/ruby/gems/1.8/gems/rails-1.0.0/lib/webrick_server.rb:83:in
`service''
c:/ruby/lib/ruby/1.8/webrick/httpserver.rb:104:in `service''
c:/ruby/lib/ruby/1.8/webrick/httpserver.rb:65:in `run''
c:/ruby/lib/ruby/1.8/webrick/server.rb:173:in `start_thread''
c:/ruby/lib/ruby/1.8/webrick/server.rb:162:in `start_thread''
c:/ruby/lib/ruby/1.8/webrick/server.rb:95:in `start''
c:/ruby/lib/ruby/1.8/webrick/server.rb:92:in `start''
c:/ruby/lib/ruby/1.8/webrick/server.rb:23:in `start''
c:/ruby/lib/ruby/1.8/webrick/server.rb:82:in `start''
c:/ruby/lib/ruby/gems/1.8/gems/rails-1.0.0/lib/webrick_server.rb:69:in
`dispatch''
c:/ruby/lib/ruby/gems/1.8/gems/rails-1.0.0/lib/commands/servers/webrick.rb:59
c:/ruby/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:21:in
`require''
c:/ruby/lib/ruby/gems/1.8/gems/activesupport-1.2.5/lib/active_support/dependencies.rb:214:in
`require''
c:/ruby/lib/ruby/gems/1.8/gems/rails-1.0.0/lib/commands/server.rb:28
c:/ruby/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:21:in
`require''
c:/ruby/lib/ruby/gems/1.8/gems/activesupport-1.2.5/lib/active_support/dependencies.rb:214:in
`require''
script/server:5|


    Request

*Parameters*: None

Show session dump <http://localhost:3000/test#>

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



    Response

*Headers*: {"cookie"=>[],
"Cache-Control"=>"no-cache"}

So seeing the error, I changed back ''dontcare'' to
''dn_login_id'' and
voila....
I actually did not try to add the new table to the existing application 
yet. I just created a new project to test out this. The next thing  I am 
gonna do is to integrate this apprach to my app.
And also how did you figure out this? I''ve been banging my head to the 
wall over two weeks now. Could you please explain a little more how this 
self.inheritence_colum() work? for example why do i need to have
''self''
in front of inheritence_column()?
and How do I get more information about the methods like 
inheritence_column()?
I greatly appreciate you help and again thank you.
Dnz....


-------------- next part --------------
An HTML attachment was scrubbed...
URL:
http://wrath.rubyonrails.org/pipermail/rails/attachments/20060130/f15e26a2/attachment-0001.html

Deniz,
It sounds to me like a referential integrity issue. ie.. The table that 
you are trying to change has a foreign key with ON DELETE CASCADE and/or 
ON UPDATE CASCADE constraints.  So when you attempt to change the table 
your working on the database throws an error saying in effect "You
can''t
do that because another table has a relationship to this me.  Please 
change that one first."

If you can, extract your entire db as a sql statment.  Then look for 
something like:

CONSTRAINT BOOK_SECT FOREIGN KEY (SECTION_ID) REFERENCES 
SECTION(SECTION_ID) ON DELETE CASCADE

It looks as if it may be DN_LOGIN_ID.  Is that a three digit entry?

The foreign key may not be in the table your working on.  Look for a 
foreign ke reference to a row in your current table from another table.

Then again I could be totally off base. Crack being what it is and all.

Scott.



-- 
Posted via http://www.ruby-forum.com/.

Deniz wrote:
> Alex Young wrote:
<snip>
> So seeing the error, I changed back ''dontcare'' to
''dn_login_id'' and
> voila....
> I actually did not try to add the new table to the existing application 
> yet. I just created a new project to test out this. The next thing  I am 
> gonna do is to integrate this apprach to my app.
> And also how did you figure out this? 
I thought I''d figured something out about data dependence (it had to be
doing something weird and data-related to be calling empty? on something 
that clearly wasn''t internal to Rails), and then I spotted the first 
line of the trace you emailed:

c:/ruby/lib/ruby/gems/1.8/gems/activerecord-1.13.2/lib/active_record/base.rb:890:in
`instantiate_without_callbacks''

Lines 889 and 890 look like this:

   if subclass_name = record[inheritance_column]
     if subclass_name.empty?

Once I saw inheritance_column in there, and with your schema info 
available, it clicked.
> Could you please explain a little more how this 
> self.inheritence_colum() work? 
It''s a class method that returns a single string.  That string is used 
(by a few other places in the code) to find the column which holds the 
class name data for ActiveRecord subclasses to be instantiated as. 
It''s
documented clearer than I could probably explain it at 
http://api.rubyonrails.com/classes/ActiveRecord/Base.html.
> for example why do i need to have ''self'' 
> in front of inheritence_column()?
That''s because it''s a class method, rather than an instance
method.
Check here for more details: 
http://www.rubycentral.com/book/tut_classes.html

Basically, it means that Rails doesn''t need an instance of the class 
before it can find the information it needs to correctly create 
instances.  It''s a like a singleton method, if that terminology means 
anything to you.
> and How do I get more information about the methods like 
> inheritence_column()?
See http://api.rubyonrails.com.  Oh, and the source code :-)
> I greatly appreciate you help and again thank you.
No worries :-)
Oh, and a quick pointer, before you run into any more problems (although 
you may have spotted this already) - You''re going to need to call 
set_primary_key in CfgDn, because ActiveRecord won''t know which column 
is unique in that table.  Check the docs for more info on that.

-- 
Alex

Scott wrote:
>Deniz,
>It sounds to me like a referential integrity issue. ie.. The table that 
>you are trying to change has a foreign key with ON DELETE CASCADE and/or 
>ON UPDATE CASCADE constraints.  So when you attempt to change the table 
>your working on the database throws an error saying in effect "You
can''t
>do that because another table has a relationship to this me.  Please 
>change that one first."
>
>If you can, extract your entire db as a sql statment.  Then look for 
>something like:
>
>CONSTRAINT BOOK_SECT FOREIGN KEY (SECTION_ID) REFERENCES 
>SECTION(SECTION_ID) ON DELETE CASCADE
>
>It looks as if it may be DN_LOGIN_ID.  Is that a three digit entry?
>
>The foreign key may not be in the table your working on.  Look for a 
>foreign ke reference to a row in your current table from another table.
>
>Then again I could be totally off base. Crack being what it is and all.
>
>Scott.
>
>
>
>  
>
Scott,
thank you for your reply. From what I saw, DN_LOGIN_ID is empty for this 
particular example. Actually DBID is three digit but what I am trying to 
do actually is to search the database with Number_. Number_ is the four 
digit actual DN I am looking for. The search was working with the DN 3 
digit entry, now I am working on to do the same thing with Number_
Thanx.
Deniz.