Rails Chops: Working with databases

References

• Read from: “The Rails Way” – Chapter 6


• Active Record Presentation


• Migrations Presentation (ignore mysql at beginning)

Objectives

• Configure Rails to work with a database (database.yml)


• create table (migration)


• use ActiveRecord to interact with our database


• use script/console to learn how ActiveRecord works

Model

• handle application state (usually in the database)


• encapsulate business logic, such as data validation and rules applied to data

ActiveRecord

• ORM (object-relational mapping)


• Instead of dealing with database through SQL statements, ORM layer presents records as a collection of objects


• Table represents a collection of objects(stories)


• Record represents an object/model (story)


• Field represents an object attribute (title)

CRUD operations on database

• C: create, insert record into table


• R: read, select record(s) from table


• U: update, update record(s) in the table


• D: delete, delete record(s) from the table