- Learning Ruby on Rails
- Rails 2.1 Home
- Rails 2.1 Introduction
- Rails 2.1 Installation
- Rails 2.1 Framework
- Rails 2.1 Dir Structure
- Rails 2.1 Examples
- Rails 2.1 Database Setup
- Rails 2.1 Active Records
- Rails 2.1 Migrations
- Rails 2.1 Controllers
- Rails 2.1 Views
- Rails 2.1 Layouts
- Rails 2.1 Scaffolding
- Rails 2.1 and AJAX
- Rails 2.1 Uploads Files
- Rails 2.1 Sends Emails
- Advanced Ruby on Rails 2.1
- Rails 2.1 RMagick Guide
- Rails 2.1 Basic HTTP Auth
- Rails 2.1 Error Handling
- Rails 2.1 Routes System
- Rails 2.1 Unit Testing
- Advanced Ruby on Rails 2.1
- Rails 2.1 Tips & Tricks
- Quick Reference Guide
- Quick Reference Guide
- Ruby on Rails 2.1 Useful Resources
- Ruby on Rails 2.1 - Resources
- Ruby on Rails 2.1 - Discussion
- Selected Reading
- UPSC IAS Exams Notes
- Developer's Best Practices
- Questions and Answers
- Effective Resume Writing
- HR Interview Questions
- Computer Glossary
- Who is Who
Ruby on Rails 2.1 - The Maths Functions
Consider a table object called Person. This table has fields like age, first_name, last_name, and salary.
The following code will return the average age of all the employees.
Person.average :age
The following code will return the maximum age of the employees.
Person.maximum :age
The following code will return the minimum age of the employees.
Person.minimum :age
The following code will return the sum of salaries of all the employees.
Person.sum :salary, :group => :last_name
The following code will count the number of records having age more than 26.
Person.count(:conditions => "age > 26")
The following code will count the total number of records.
Person.count
rails-quick-guide.htm
Advertisements