Active Record #notes

ActiveRecord.md

Active Record

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Active Record tracks which migrations have already been run so all you have to do is update your source and run rake db:migrate. Active Record will work out which migrations should be run. It will also update your db/schema.rb file to match the structure of your database.

INDEX

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• References

INBOX

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• migrations for schema creation

• validations

• one-to-may association

• many-to-many association

• spec tests

• Schema

• Associations

• Migrations

  • symmetric

• TDD models and migrations

• Scrub and import data

• AR queries

• single-table inheritance

• internalize schema

class AddCanFireMissilesFlagToUsers < ActiveRecord::Migration
  def change
    add_column :users, :can_fire_missiles, :boolean, :default => false
  end
end

Migrations

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Supported database column types:*

• binary
• boolean
• date
• datetime
• decimal
• float
• integer
• primary_key
• string
• text
• time
• timestamp

Migrations are classes

Active Record provides methods that perform common data definition tasks in a database independent way:

• add_column
• add_index
• change_column
• change_table
• create_table
• drop_table
• remove_column
• remove_index
• rename_column

REFERENCES

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Source Code

Rails Docs

Rails Guides:

• Migrations
• Validations & Callbacks
• Associations
• Query Interface

net tuts

Prado Quickstart Tutorial

Related Projects

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• ar-student-schema
• ActiveRecord-TODO