MiniRecord is a micro extension for our ActiveRecord gem. With MiniRecord you can add the ability to create columns outside the default schema.rb, directly in your model in a similar way that should know in others projects like DataMapper, MongoMapper or MongoID.

My inspiration come from this handy project.

• Define columns/properties inside your model
• Perform migrations automatically
• Auto upgrade your schema, so if you know what you are doing you don't lose your existing data!
• Add, Remove, Change Columns; Add, Remove, Change indexes

What you need is to move/remove your db/schema.rb. This avoid conflicts.

Add to your Gemfile:

gem 'mini_record'

That's all!

Remember that inside properties you can use all migrations methods, see documentation

class Post < ActiveRecord::Base
  col :title_en, :title_jp
  col :description_en, :description_jp, :as => :text
  col :permalink, :index => true, :limit => 50
  col :comments_count, :as => :integer
  col :category, :as => :references, :index => true
end
Post.auto_upgrade!

If you don't like col there are also few aliases: key, field, property, attribute

Instead of :as => :my_type you can use :type => :my_type

Option :as or :type if not provided is :string by default, you can use all ActiveRecord types:

:primary_key, :string, :text, :integer, :float, :decimal, :datetime, :timestamp, :time,
:date, :binary, :boolean, :references, :belongs_to, :timestamp

You can provide others ActiveRecord options like:

:limit, :default, :null, :precision, :scale

# example
class Foo < ActiveRecord::Base
  col :title, :default => "MyTitle" # :as => :string is by default
  col :price, :as => :decimal, :scale => 8, :precision => 2
end

See ActiveRecord::TableDefinition for more details.

Finally, when you execute MyModel.auto_upgrade!, missing columns, indexes and tables will be created on the fly. Indexes and columns present in the db but not in your model schema will be deleted* also in your db.

MiniRecord as ActiveRecord support STI plus some goodness, see our specs for more details.

MiniRecord has built-in support of belongs_to, belongs_to polymorphic and habtm relations. Just declaring these in your model will generate the necessary id columns, indexes and join tables

class Address < ActiveRecord::Base
  belongs_to :person
end

Will result in a person_id column (you can override with the foreign_key option) which is indexed

class Address < ActiveRecord::Base
  belongs_to :person
  index :person_id, :foreign => true
end

The same as in the previous case, but foreign key will be added to the database with help of foreigner gem.

To remove the key please use :foreign => false If you simple remove the index, the foreign key will not be removed.

class Address < ActiveRecord::Base
  belongs_to :addressable, :polymorphic => true
end

Will result in addressable id and type columns with composite indexes add_index(:addresses), [:addressable_id, :addressable_type]

class Address < ActiveRecord::Base
  has_and_belongs_to_many :people
end

Will generate a "addresses_people" join table and index the id columns

Super easy, open your model and just add it:

class Post < ActiveRecord::Base
  col :title
  col :body, :as => :text # <<- this
  col :permalink, :index => true
  col :comments_count, :as => :integer
  col :category, :as => :references, :index => true
end
Post.auto_upgrade!

So now when you invoke MyModel.auto_upgrade! you should see a SQL query like ALTER TABLE that mean that your existing records are happy and safe.

It's exactly the same, but the column will be really deleted without affect other columns.

Simply add a rename_col declaration and mini_record will do a connection.rename_column in the next auto_upgrade! but only if the db has the old column and not the new column. You still need to have a col declaration for the new column name so subsequent MyModel.auto_upgrade! will not remove the column. You are free to leave the rename_col declaration in place or you can remove it once the new column exists in the db.

Moving from:

class Vehicle < ActiveRecord::Base
  col :color

To:

class Vehicle < ActiveRecord::Base
  rename_col :color, :new_name => :body_color
  col :body_color
end

Then perhaps later:

class Vehicle < ActiveRecord::Base
  rename_col :color, :new_name => :body_color
  rename_col :body_color, :new_name => :chassis_color
  col :chassis_color

It's not possible for us know that the column name changed, if you modify the name in a col declaration, but we can know if you changed the type so if you change t.string :name to t.text :name we are be able to perform an ALTER TABLE

In the same ways we manage columns MiniRecord will detect new indexes and indexes that needs to be removed. So when you perform MyModel.auto_upgrade! a SQL command like:

PRAGMA index_info('index_people_on_name')
CREATE INDEX "index_people_on_surname" ON "people" ("surname")

Note that writing it in DSL way you have same options as add_index so you are be able to write:

class Fox < ActiveRecord::Base
  col :foo, :index => true
  col :foo, :index => :custom_name
  col :foo, :index => [:foo, :bar]
  col :foo, :index => { :column => [:branch_id, :party_id], :unique => true, :name => 'by_branch_party' }
end

That is the same of:

class Fox < ActiveRecord::Base
  col :foo
  add_index :foo
  add_index :custom_name
  add_index [:foo, :bar]
  add_index [:branch_id, :party_id], :unique => true, :name => 'by_branch_party'
end

DAddYE, you can follow me on twitter @daddye or take a look at my site daddye.it

Copyright (C) 2011 Davide D'Agostino - @daddye

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