title: "pg is not part of the bundle. Add it to Gemfile" when not using Postgres
body: <p>Here's my problem: </p>
  
  <ul>
  <li><p>I create a new project: <code>rails new myapp</code>.<br>
  Rails applications are by default configured to use a SQLite3 database. </p></li>
  <li><p>I execute <code>bundle exec rake db:create</code>. It works and the SQLite3 database is created. </p></li>
  <li><p>I try to create a new model (or anything else related to the database), and get the following error: </p>
  
  <blockquote>
    <p>/home/dinduks/.rvm/gems/ruby-1.9.3-p194/gems/bundler-1.1.3/lib/bundler/rubygems_integration.rb:147:in <code>block in replace_gem': Please install the postgresql adapter:</code>gem install activerecord-postgresql-adapter` (pg is not part of the bundle. Add it to Gemfile.) (LoadError) </p>
  </blockquote></li>
  <li><p>When I add a controller and an action, and try to visit it, I get this error: </p>
  
  <blockquote>
    <p>ActiveRecord::ConnectionNotEstablished (ActiveRecord::ConnectionNotEstablished)</p>
  </blockquote>
  
  <p>The complete stack trace can be found here: <a href="https://gist.github.com/2717365" rel="nofollow">https://gist.github.com/2717365</a><br>
  The WEBrick server starts obviously without complaining. </p></li>
  </ul>
  
  <p>I reinstalled Rails, reinstalled Ruby, used another Ruby version, reinstalled RVM... And keep getting the same error.</p>
  
  <p>There is <strong>nothing</strong> related to <em>PostgreSQL</em>, <em>postgres</em>, <em>pg</em> or <em>pql</em> in my code. Not a single word. </p>
  
  <p>I don't want to do what the exception suggests. I want to understand why I have this error and fix it. </p>
  
  <p>So: Why is Rails asking me to install some Postgres stuff while <strong>I don't use Postgres</strong>? </p>
  
  <p>Thanks!</p>