MongoDB & Rails

Intro to using MongoDB with Rails. Presented at Madrid-rb

Transcript

1. MongoDB & Rails madrid-rb
2. Amaia Castro Freelance Ruby on Rails developer amaiacastro.com github.com/amaia @amaiac
4. RDBMS Memcached MongoDB NoSQL SQL features scale & speed
5. MongoDB Dynamic queries Secondary indexes Joins Transactions Referential integrity
6. Document
7. "JSON" { name: "mongo", type: "DB" }
8. Collections of documents
9. MongoDB + Rails = Mongoid (Object-Document-Mapper) Queries Validations Callbacks Associations
10. Tags posts tags SQL MongoDB posts_tags ------------ post_id tag_id { title: "MongoDB", tags: [ "mongodb", "madrid-rb", "ruby" ] } posts class Post include Mongoid:: Document field :title field :tags, type: Array end
11. Invoice invoice invoice_line ------------ invoice_id SQL MongoDB { invoice_number: "01", invoice_lines: [ {...}, {...} ] }
12. class Invoice include Mongoid::Document field :number, type: String embeds_many :invoice_lines end class InvoiceLine include Mongoid::Document field :description, type: String field :price, type: BigDecimal embedded_in :invoice end
13. Users & Groups users groups SQL MongoDB groups_users ------------ user_id group_id { _id: "abc123", username: "amaia", groups: [ "654dbd", ... ] } { _id: "654dbd", name: "madrid- rb", users: [ "abc123", ... ] } users groups
14. Real Life Example
15. ActiveRecord + Mongoid config ├── database.yml └── mongoid.yml tip: activate safe_mode in mongoid.yml
16. class PersonalProfile include Mongoid::Document field :user_id, :type => Integer field :name, :type => String field :interests, :type => Array field :skills, :type => Array def user User.find_by_id(self.user_id) end end class User < ActiveRecord::Base def personal_profile PersonalProfile.where(user_id: self.id).first end end
17. • No joins or transactions at DB level • Model your data as independent documents • Avoid referenced associations in Mongoid • Mix and match SQL and NoSQL when needed Summary
18. Thank you