Integrate Postgresql database with Ruby Application - ruby-on-rails

Question

I just started building my very first Ruby on Rails application and in order for me to host it on heroku I have change my database setting in my application. I did just that by changing the database.yml file in my application. This is what I have in it now.
# SQLite version 3.x
# gem install sqlite3-ruby (not necessary on OS X Leopard)
development:
adapter:postgresql
encoding:unicode
database:dezirus_dev
pool:5
host:localhost
username:postgres
password:
port:5432
# timeout: 5000
# Warning: The database defined as "test" will be erased and
# re-generated from your development database when you run "rake".
# Do not set this db to the same as development or production.
test:
adapter:postgresql
encoding:unicode
database:dezirus_test
pool:5
username:postgres
password:
host:localhost
port:5432
production:
adapter:postgresql
encoding:unicode
database:dezirus
pool:5
username:postgres
password:
host:localhost
port:5432
When i try to rake the DB this is the error I get.
RAHMAN#IMLDEV1-LT ~/rails-projects/dezirus
$ rake db:migrate --trace
rake aborted!
no such file to load -- pg
/usr/lib/ruby/gems/1.8/gems/bundler-1.0.22/lib/bundler/runtime.rb:68:in `require'
/usr/lib/ruby/gems/1.8/gems/bundler-1.0.22/lib/bundler/runtime.rb:68:in `require'
/usr/lib/ruby/gems/1.8/gems/bundler-1.0.22/lib/bundler/runtime.rb:66:in `each'
/usr/lib/ruby/gems/1.8/gems/bundler-1.0.22/lib/bundler/runtime.rb:66:in `require'
/usr/lib/ruby/gems/1.8/gems/bundler-1.0.22/lib/bundler/runtime.rb:55:in `each'
/usr/lib/ruby/gems/1.8/gems/bundler-1.0.22/lib/bundler/runtime.rb:55:in `require'
/usr/lib/ruby/gems/1.8/gems/bundler-1.0.22/lib/bundler.rb:122:in `require'
/home/RAHMAN/rails-projects/dezirus/config/application.rb:7
/usr/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:36:in `gem_original_require'
/usr/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:36:in `require'
/home/RAHMAN/rails-projects/dezirus/Rakefile:4
/usr/lib/ruby/gems/1.8/gems/rake-0.9.2.2/lib/rake/rake_module.rb:25:in `load'
/usr/lib/ruby/gems/1.8/gems/rake-0.9.2.2/lib/rake/rake_module.rb:25:in `load_rakefile'
/usr/lib/ruby/gems/1.8/gems/rake-0.9.2.2/lib/rake/application.rb:501:in `raw_load_rakefile'
/usr/lib/ruby/gems/1.8/gems/rake-0.9.2.2/lib/rake/application.rb:82:in `load_rakefile'
/usr/lib/ruby/gems/1.8/gems/rake-0.9.2.2/lib/rake/application.rb:133:in `standard_exception_handling'
/usr/lib/ruby/gems/1.8/gems/rake-0.9.2.2/lib/rake/application.rb:81:in `load_rakefile'
/usr/lib/ruby/gems/1.8/gems/rake-0.9.2.2/lib/rake/application.rb:65:in `run'
/usr/lib/ruby/gems/1.8/gems/rake-0.9.2.2/lib/rake/application.rb:133:in `standard_exception_handling'
/usr/lib/ruby/gems/1.8/gems/rake-0.9.2.2/lib/rake/application.rb:63:in `run'
/usr/lib/ruby/gems/1.8/gems/rake-0.9.2.2/bin/rake:33
/usr/bin/rake:23:in `load'
/usr/bin/rake:23
Please note that the database was prebuilt using postgreSQL and i already have my tables, primary and foreign keys set. I'm not sure if maybe this is why its refusing to work or not. Any help would be really appreciated. Thanks

Answer 1

First install PG in your computer, http://www.postgresql.org/download/
Try opening it with PGAdmin3 (DB administrator it comes with) and create a new BD
next in your gem file add this
gem 'pg'
run bundle install at terminal.
and here i send you an example of my DB.yml
development:
adapter: postgresql
encoding: unicode
database: billy
pool: 5
username: postgres
password:
You may need to configure the pg_hba.conf to login without a password in your localhost.

Answer 2

Add gem 'pg' to your gem file and run
bundle install
Then go here http://www.postgresql.org/download/ and install the database to your machine in order to run your app locally.

Answer 3

Hey guys I finally found a solution for the different issues I had. It turns out that cygwin pg gem does not support my version of PostgreSQL, I used the ruby installer and It installed without a flinch. I then used had to add this line of code to the boot.rb file
require 'yaml'
YAML::ENGINE.yamler = 'syck'
The YML file too needs to look something like this.
development:
adapter: postgresql
encoding: unicode
database: dezirus_dev
pool: 5
username: postgres
password:
# Warning: The database defined as "test" will be erased and
# re-generated from your development database when you run "rake".
# Do not set this db to the same as development or production.
test:
adapter: postgresql
encoding: unicode
database: dezirus_test
username: postgres
password:
production:
adapter: postgresql
encoding: unicode
database: dezirus
username: sudo
password: *******
I then ran the rake db:migrate command and voila :)