Category: Ruby On Rails

Set up Ruby on Rails from http://rubyonrails.org/download. Make a directory ‘my_rails’ in your home folder for rails applications.
$ cd my_rails

create your application as following
$ rails new student_db
$ cd student_db
For including gems, you need to update the Gemfile, that resides in your application folder. Open the ‘Gemfile’ and update.

Gemfile :
source ‘http://rubygems.org’
gem ‘rails’, ‘3.0.0’
gem ‘sqlite3-ruby’, ‘1.2.5’, :require => ‘sqlite3’

Specify the version number for sqlite3.    This is for avoiding confusion while installing the gems.

Install gems
$ bundle install

Now you are ready to generate the student model. Use scaffold generator.

Note : Rails developers dislike scaffold. Because it itself generates code. So don’t use it. This is only for referring the application.
$ rails generate scaffold Student first_name:string last_name:string roll_no:integer total_mark:integer

Migrate the database using rake.

$ rake db:migrate

Now run the server.

$ rails s

open the browser and go to http://localhost:3000/student

To see this application visit,
Student_data_base

Sign up using e-mail and a password.
http://heroku.com/
Then Heroku asks to check our mail and continue. Install git. Then Install heroku gem.

$ gem install heroku
Create SSH keys and tell Heroku the public key by
$ heroku keys:add
Create a new application in Heroku
$ heroku create
Then Heroku creates a random sub domain for our application. We can change it as we like. Then deploy the app to Heroku by
$ git push heroku master
Now we can visit our application by using the address.

Heroku provides different plans to deploy the application and for using the database space. Here the plan is Blossom. It is free and can take 5MB database maximum.

Git is a version control system and a very good friend of a developer. Todays all projects are very much depend on git. What’s the use of git? If a programmer develops a project he want to take copies of the progressing project at stage by stage. Using git we can ‘commit’ the project by giving comments like ‘first commit’ , ‘second commit’ etc. When a programmer deletes a file, he can recover the file using git. Git uses a tree structure to hold the data. It has a parent repository called master branch. We can change the branch to another and can process the data. Multiple branches are using when working on a projects with multiple developers. This branch master is unaltered when working on another branch. Download .rpm packages from RPM packages, and .deb packages from Debian Packages