On-the-fly schema changes for very rapid prototyping, for ActiveRecord and Sequel ORMs.
Loosely define your schema in your model and have it created and updated for you without worrying about migrations.
Useful for when you want to play around with real data handling during prototyping but you really don't care about keeping the data or how it's defined.
This isn't meant to be a replacement for migrations, it is simply a way to get started on a project quickly while you iron out your data definitions.
WARNING: This will create and delete data definitions on the fly with no warning! Only use this with volatile data! Never attach it to an existing model you care about as it will start adding and dropping columns without your consent!
$ gem install schemer
require "schemer/active_record"
class User < ActiveRecord::Base
schema :username, :password
end
Creates a users table if it doesn't exist, complete with username and
password columns the first time the User class is loaded.
Need another column to play with?
class User < ActiveRecord::Base
schema :username, :password, :email
end
Adds an email column the next time User class is loaded.
Want a relationship? (but fear commitment...)
class Widget < ActiveRecord::Base
schema :user_id, :name
belongs_to :user
end
Works just fine, and you can drop it at any time!
class Widget < ActiveRecord::Base
schema :name
end
Removes the user_id column the next time the Widget class is loaded.
Have a need for a particular type of column?
class Widget < ActiveRecord::Base
schema :name, { :size => :integer }, :description
end
Will create size as an :integer column so you can take advantage of type
loading.
Feeling more confident and ready to make that big leap to migrations? Run:
rake schemer:migration
To get:
Migration from schema declarations in User, Widget
create_table :users do |t|
t.string :username
t.string :password
t.string :email
end
create_table :widgets do |t|
t.string :name
t.integer :size
t.string :description
end
Then you can paste the output into a migration file, setup your columns (don't
forget your indexes!) and get rid of your schema calls in the listed classes
and you're on your way to the big leagues!
NOTE: All columns are created as string columns unless type is given.
require "schemer/sequel"
class Widget < Sequel::Model
plugin Schemer::Sequel
schema :name, { :size => :integer }, :description
end
Usage is as above w/ ActiveRecord
$ rake
Michel Martens (soveran) + Cyril David (cyx) for helping with Sequel support.
Copyright (c) 2009-2011 Ben Alavi for Citrusbyte
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