Using hybriddb with a rails app - first thoughts

I just converted a few apps to use hybriddb instead of ActiveRecord and I thought I’d share the experience.

Overall it was easy with a few Gotchas. For info I was using Rails 2.1

To stop using ActiveRecord in your Rails app, do the following:

Add hybriddb.rb and the hybrid_db folder from the lib directory in the hybriddb download, into the lib folder in your Rails app.

Then modify environment.rb to: load hybriddb, tell rails not to load the ActiveRecord framework, and initialize the hybriddb connection. This required adding three lines:

#environment.rb
require File.join(File.dirname(__FILE__), 'boot')
require File.join(File.dirname(__FILE__), '../lib/hybriddb.rb') #Added
Rails::Initializer.run do |config|
   config.frameworks -= [:active_record ] #Added
   config.action_controller.session = { :session_key => "_xxxx", :secret => "xxxxxxxx" }
end
#Added the line below
HybridDB::Connection.set_adapter(MySQLAdapter.new({:host=> 'localhost', :user => 'sqllogin', :password => 'sqlpassword', :database => 'testapp' }))

DO NOT delete database.yaml as Rails bugs out if it is not present, even if you don’t use activerecord.

Change your models to inherit from HybridObject instead of ActiveRecord::Base.

Explicitly add attr_accessors (or your own getters, setters and instance variable initializers) for your object properties, I simply used the schema definitions as a basis for this.

Remove belongs_to statements, they are no longer needed, simply add a property to your object and set it to another object. HybridDb will take care of stubbing it and saving the related object if necessary.

Remove join table models and has_many :through, just use has_many to initialize HybridCollections.

Change any code that uses your_model_object.id to your_model_object.hybrid_id.

Change YourModelObject.find_by_xxx(‘foo’) to explicit YourModelObject.find(:first, :conditions => {:xxx = ‘foo’})

Thoughts:

It all worked well, I was actually surprised that it went so smoothly

It was weird not viewing data in the db but actually adding records for test etc. via script.console only

The foo.hybrid_id instead of foo.id property annoyed me so much that I might make id an alias for hybrid_id (possibly via a switch as I initially wanted users to be able to add an id property for models)

It’s nice to see all your properties listed as accessors in your models

You have to remember to add an indexes statement to your models if you want to do a find on a property.

I like doing all searching etc, in pure Ruby. Manipulating collections as Arrays is great.

I think I need to add object initialization from a hash like in ActiveRecord, I was avoiding this as I didn’t want to override initialize, but doing Foo.new(:name => ‘bar’, ;age => 99) is great shorthand.

• Tags hybriddb, rails
• Meta permalink, rss, atom

HybridDB site is released

I have put this site up to accompany the HybridDB project.

HybridDB is a hybrid object/relational database. Objects are stored as ruby objects and MySQL is used for indexing and easy backup/restore clustering etc.

• No SQL
• No Migrations
• Ruby objects (Object properties can be arrays, ranges, other objects)

This is a very early release of the project and I would like people to take it for a spin and let me know of any issues they find.

Feel free to comment on the code or whether you think the project is a waste of time (or has been done before)

Download

You can download the code here

Or get it in GitHub (github.com/pauliephonic)

Tests

There are a large number of (messy) tests in the test folder.

Set your mysql connection details in theHybridDB::Connection.set_adapter line in config/environment.rb to an instance and database on your server to run them.

Tutorials

There is also a tutorials sub-folder with the download, you can follow along with the tutorial article (below) and the included tutorial code.

To Do

There is some outstanding cleanup to be done (the code is spotted with TODOs, mainly notes for me to extract code to hybrid_adapters) and I have added a To Do page (link below) for items that i will be adding in the near future.

I also have an experimental section that I’ll be updating with outlandish ideas for using and extending HybridDB

• Tags hybriddb, intro
• Meta no trackbacks, permalink, rss, atom