Ruby (not Rails) giving a NoMethodError when using find()

Question

I have a couple of scripts that interact with a MySQL database using ActiveRecord without the rest of the Rails package (although I have the complete Rails gem installed). However, trying to use these classes lately has been giving me the NoMethodError when I try to call find() on my ActiveRecord-descended class.
The class code is amazingly basic:

class LineItem <ActiveRecord::Base
   set_primary_key 'id'
   set_table_name  "line_items"
end

And yes, since I'm using a MySQL database I have a db connector file:

require 'rubygems'
require 'active_record'
require 'logger'
ActiveRecord::Base.establish_connection(
  :adapter =>'mysql',
  :database=>'my_db',
  :username=>'my_user',
  :password=>'a_password',
  :host=>"ip_address",
  :port=>3306
)
ActiveRecord::Base.logger = Logger.new(STDERR)

But when I run the script:

require "dbconn"
require "lineitem"

li = LineItem.new()
li.find(1)

I get the error:

NoMethodError: undefined method `find' for #<LineItem id: nil, trans_id: nil, trans_code: nil, data: nil>
from /Library/Ruby/Gems/1.8/gems/activerecord-2.3.3/lib/active_record/attribute_methods.rb:260:in `method_missing'
from (irb):4

If anybody has any advice I would appreciate it. I'm using Ruby 1.8.7 on OSX 10.6.1 Yes, it worked fine on 10.5.x

Answer 1

Isn't find a class method instead of an instance method?

Answer 2

You can use the find method only with data that is already in the database not with an empty ActiveRecord object like the one in your example.

Answer 3

It is quite normal for active_record objects not to have a find method (unless the corresponding table in the database has a column "find", but then that method would not take any arguments).

I think you want to do li = LineItem.find(1)