Using ActiveRecord inside another class

Question

I'm trying to set up an IRC bot using ActiveRecord on the back end to handle all the data heavy lifting (probably overkill, but this is partly a learning experience for me :3)

The issue I'm running in to is that, after defining my database schema, later on in the same script when I try to reference the table I created, I get an error from the SQLite gem saying that it could not find the table.

Furthermore, my IDE (RubyMine) complains that it is "Unable to find the rails model for :notes association field"

Something tells me this would not be happening if I weren't constrained from operating as a class of the bot framework, but that is only a wild guess at this point.

What am I doing wrong here?

require 'cinch'
  require 'active_record'
  puts 'Memobox loaded'
  class Memobox
    include Cinch::Plugin
    ActiveRecord::Base.establish_connection(
        :adapter => 'sqlite3',
        :database => ':memory:'
    )
    ActiveRecord::Schema.define do
      create_table :notes do |table|
        table.column :id, :integer
        table.column :timeset, :DateTime
        table.column :sender, :string
        table.column :recipient, :string
        table.column :text, :string
      end
    end

  class Note < ActiveRecord::Base
     has_many :notes
  end

   match(/note.*/, :prefix => "?")
   def execute(m)
    Memobox::Note.create(
        :timeset => (Time.new).ctime,
        :sender  => m.user.nick,
        :text => m.message,
        :recipient => (m.message).split("_").at(1)
        )

   end
  end

Error:

 C:/Ruby193/lib/ruby/gems/1.9.1/gems/activerecord-3.2.8/lib/active_record/connection_adapters/sqlite_adapter.rb:472:in `table_structure': Could not find table 'notes' (ActiveRecord::StatementInvalid)

Yes, if I'm understanding this right, the Note class is what i'll call to add and delete notes from my database, and I do that using the notes table I created above. Class note has many notes (database rows) — Mikey T.K., Oct 23 '12 at 05:35
`has_many` and cie. are used to declare associations between different models. Not between a table and a class. For instance, one employer `has_many` :employees. This is two different models for two different tables. You don't need anything in your case. — oldergod, Oct 23 '12 at 05:52

score 1 · Accepted Answer · answered Oct 23 '12 at 07:42

1

You should replace this

class Note < ActiveRecord::Base
  has_many :notes
end

with

class Note < ActiveRecord::Base
end

The descendants of ActiveRecord::Base class represents single row in a table, not a whole table. So to find some note by id you need just to call Note.find(123), where 123 is the id of note record in db table.

answered Oct 23 '12 at 07:42

Hck

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This ended up being part of the problem, the other part being the jankyness of in memory tables (as shown below). Thanks! – Mikey T.K. Nov 19 '12 at 14:59

score 0 · Answer 2 · answered Oct 23 '12 at 19:29

Thanks to everyone for the clarification on the use of has_many and the syntax, but my problem ended up being the use of an in memory table instead of an on disk one. Once I changed line seven to say

:database => 'notes.db'

instead of

:database => ':memory:'

and removed the has_many declaration from the Notes class (I did try it without doing this and got a different error) , everything works :)

Using ActiveRecord inside another class

2 Answers2