undefined method `eq' for nil:NilClass

I'm walking through an example in the "Head First Rails" book, but,
instead doing the examples using Rails3.0.0.rc.

But, I'm getting this error when browsing for example:

http://localhost:3000/advs/1

undefined method `eq' for nil:NilClass

Provided that my advs_controller.rb is as follows:

http://pastie.org/private/cd9zntg2ite57ept288kfa

Any ideas why I'm getting that and a workaround for that?

Thanks.

I'm walking through an example in the "Head First Rails" book, but,
instead doing the examples using Rails3.0.0.rc.

But, I'm getting this error when browsing for example:

http://localhost:3000/advs/1

undefined method `eq' for nil:NilClass

For an error like this it is better to show the full error trace, but
first look at it yourself. Somewhere there you will usually find a
reference to a line of your code. Look carefully at that line and the
error and try and work out the problem yourself. The error is saying
that you are trying to call a method on an object that is nil. A
common cause of this is using the result of a find operation without
checking that it did in fact find a record.

If you still cannot see the problem then post the error trace and the
code around the error.

Provided that my advs_controller.rb is as follows:

http://pastie.org/private/cd9zntg2ite57ept288kfa

For only a few lines of code it is better in my opinion to put it
inline rather than a pastie. Particularly consider those who may find
the thread in months and years yet to come, hoping for enlightenment,
only to find that the pastie has disappeared.

Colin

What does your view look like?

Thanks for your replies.

The issue was as follows:

As I mentioned, I'm walking through an example in "Head First Rails". I
have used the book's version of "development.sqlite3" that contains some
data.

I used the name "advs" to create my application, and the table name in
the database version I used happen to have the name "ads".

So, I just changed the name of the table to "advs" and it worked.

Thanks.

Hi,

Me too got same error... I attached Full trace here... Kindly suggest
on this issue...

undefined method `eq' for nil:NilClass

activesupport (3.0.0) lib/active_support/whiny_nil.rb:48:in
`method_missing'
activerecord (3.0.0) lib/active_record/relation/finder_methods.rb:
291:in `find_one'
activerecord (3.0.0) lib/active_record/relation/finder_methods.rb:
281:in `find_with_ids'
activerecord (3.0.0) lib/active_record/relation/finder_methods.rb:
107:in `find'
activerecord (3.0.0) lib/active_record/base.rb:439:in `find'
app/models/taxa.rb:2:in `<class:Taxa>'
app/models/taxa.rb:1:in `<top (required)>'
activesupport (3.0.0) lib/active_support/dependencies.rb:454:in `load'
activesupport (3.0.0) lib/active_support/dependencies.rb:454:in `block
in load_file'
activesupport (3.0.0) lib/active_support/dependencies.rb:591:in
`new_constants_in'
activesupport (3.0.0) lib/active_support/dependencies.rb:453:in
`load_file'
activesupport (3.0.0) lib/active_support/dependencies.rb:340:in
`require_or_load'
activesupport (3.0.0) lib/active_support/dependencies.rb:491:in
`load_missing_constant'
activesupport (3.0.0) lib/active_support/dependencies.rb:183:in `block
in const_missing'
activesupport (3.0.0) lib/active_support/dependencies.rb:181:in `each'
activesupport (3.0.0) lib/active_support/dependencies.rb:181:in
`const_missing'
activesupport (3.0.0) lib/active_support/dependencies.rb:503:in
`load_missing_constant'
activesupport (3.0.0) lib/active_support/dependencies.rb:183:in `block
in const_missing'
activesupport (3.0.0) lib/active_support/dependencies.rb:181:in `each'
activesupport (3.0.0) lib/active_support/dependencies.rb:181:in
`const_missing'
app/controllers/taxas_controller.rb:5:in `index'
actionpack (3.0.0) lib/action_controller/metal/implicit_render.rb:4:in
`send_action'
actionpack (3.0.0) lib/abstract_controller/base.rb:150:in
`process_action'
actionpack (3.0.0) lib/action_controller/metal/rendering.rb:11:in
`process_action'
actionpack (3.0.0) lib/abstract_controller/callbacks.rb:18:in `block
in process_action'
activesupport (3.0.0) lib/active_support/callbacks.rb:435:in
`_run__402958380944449391__process_action__4448255831886203218__callbacks'
activesupport (3.0.0) lib/active_support/callbacks.rb:409:in
`_run_process_action_callbacks'
activesupport (3.0.0) lib/active_support/callbacks.rb:93:in
`run_callbacks'
actionpack (3.0.0) lib/abstract_controller/callbacks.rb:17:in
`process_action'
actionpack (3.0.0) lib/action_controller/metal/instrumentation.rb:
30:in `block in process_action'
activesupport (3.0.0) lib/active_support/notifications.rb:52:in `block
in instrument'
activesupport (3.0.0) lib/active_support/notifications/instrumenter.rb:
21:in `instrument'
activesupport (3.0.0) lib/active_support/notifications.rb:52:in
`instrument'
actionpack (3.0.0) lib/action_controller/metal/instrumentation.rb:
29:in `process_action'
actionpack (3.0.0) lib/action_controller/metal/rescue.rb:17:in
`process_action'
actionpack (3.0.0) lib/abstract_controller/base.rb:119:in `process'
actionpack (3.0.0) lib/abstract_controller/rendering.rb:40:in
`process'
actionpack (3.0.0) lib/action_controller/metal.rb:133:in `dispatch'
actionpack (3.0.0) lib/action_controller/metal/rack_delegation.rb:
14:in `dispatch'
actionpack (3.0.0) lib/action_controller/metal.rb:173:in `block in
action'
actionpack (3.0.0) lib/action_dispatch/routing/route_set.rb:62:in
`call'
actionpack (3.0.0) lib/action_dispatch/routing/route_set.rb:62:in
`dispatch'
actionpack (3.0.0) lib/action_dispatch/routing/route_set.rb:27:in
`call'
rack-mount (0.6.13) lib/rack/mount/route_set.rb:148:in `block in call'
rack-mount (0.6.13) lib/rack/mount/code_generation.rb:93:in `block in
recognize'
rack-mount (0.6.13) lib/rack/mount/code_generation.rb:68:in
`optimized_each'
rack-mount (0.6.13) lib/rack/mount/code_generation.rb:92:in
`recognize'
rack-mount (0.6.13) lib/rack/mount/route_set.rb:139:in `call'
actionpack (3.0.0) lib/action_dispatch/routing/route_set.rb:492:in
`call'
actionpack (3.0.0) lib/action_dispatch/middleware/
best_standards_support.rb:17:in `call'
actionpack (3.0.0) lib/action_dispatch/middleware/head.rb:14:in `call'
rack (1.2.1) lib/rack/methodoverride.rb:24:in `call'
actionpack (3.0.0) lib/action_dispatch/middleware/params_parser.rb:
21:in `call'
actionpack (3.0.0) lib/action_dispatch/middleware/flash.rb:182:in
`call'
actionpack (3.0.0) lib/action_dispatch/middleware/session/
abstract_store.rb:149:in `call'
actionpack (3.0.0) lib/action_dispatch/middleware/cookies.rb:287:in
`call'
activerecord (3.0.0) lib/active_record/query_cache.rb:32:in `block in
call'
activerecord (3.0.0) lib/active_record/connection_adapters/abstract/
query_cache.rb:28:in `cache'
activerecord (3.0.0) lib/active_record/query_cache.rb:12:in `cache'
activerecord (3.0.0) lib/active_record/query_cache.rb:31:in `call'
activerecord (3.0.0) lib/active_record/connection_adapters/abstract/
connection_pool.rb:355:in `call'
actionpack (3.0.0) lib/action_dispatch/middleware/callbacks.rb:46:in
`block in call'
activesupport (3.0.0) lib/active_support/callbacks.rb:415:in
`_run_call_callbacks'
actionpack (3.0.0) lib/action_dispatch/middleware/callbacks.rb:44:in
`call'
rack (1.2.1) lib/rack/sendfile.rb:107:in `call'
actionpack (3.0.0) lib/action_dispatch/middleware/remote_ip.rb:48:in
`call'
actionpack (3.0.0) lib/action_dispatch/middleware/show_exceptions.rb:
46:in `call'
railties (3.0.0) lib/rails/rack/logger.rb:13:in `call'
rack (1.2.1) lib/rack/runtime.rb:17:in `call'
activesupport (3.0.0) lib/active_support/cache/strategy/local_cache.rb:
72:in `call'
rack (1.2.1) lib/rack/lock.rb:11:in `block in call'
<internal:prelude>:10:in `synchronize'
rack (1.2.1) lib/rack/lock.rb:11:in `call'
actionpack (3.0.0) lib/action_dispatch/middleware/static.rb:30:in
`call'
railties (3.0.0) lib/rails/application.rb:168:in `call'
railties (3.0.0) lib/rails/application.rb:77:in `method_missing'
railties (3.0.0) lib/rails/rack/log_tailer.rb:14:in `call'
rack (1.2.1) lib/rack/content_length.rb:13:in `call'
rack (1.2.1) lib/rack/handler/webrick.rb:52:in `service'
/usr/local/lib/ruby/1.9.1/webrick/httpserver.rb:111:in `service'
/usr/local/lib/ruby/1.9.1/webrick/httpserver.rb:70:in `run'
/usr/local/lib/ruby/1.9.1/webrick/server.rb:183:in `block in
start_thread'

Hi,
This was happened when i tried to give "Model.find " option in Query interface.