title: Installing newest version of Rails 4 with Postgres - The PGconn, PGresult, and PGError constants are deprecated
body: <p>I'm not able to find this warning on Google so asking Stackowerflower's help.</p>
  
  <p>I want to install Rails 4.2.8 on fresh Centos 7 box.
  Postgres version is 9.2.18.
  Ruby version is 2.3.4.</p>
  
  <p>When Rails is installed I configure config/database.yml file as usual and pretty sure that database.yml file is ok to connect to DB successfully. Postgres is already running for other apps successfully and fresh role is created for this app.</p>
  
  <p>In the next step there is an actual issue:</p>
  
  <pre><code>[user@server dir]$ rake db:setup
  The PGconn, PGresult, and PGError constants are deprecated, and will be
  removed as of version 1.0.
  
  You should use PG::Connection, PG::Result, and PG::Error instead, respectively.
  
  Called from /home/user/.rbenv/versions/2.3.4/lib/ruby/gems/2.3.0/gems/activesupport-4.2.8/lib/active_support/dependencies.rb:240:in `load_dependency'
  /home/rent/apps/rent/db/schema.rb doesn't exist yet. Run `rake db:migrate` to create it, then try again. If you do not intend to use a database, you should instead alter /home/user/apps/rent/config/application.rb to limit the frameworks that will be loaded.
  [user@server dir]$
  </code></pre>
  
  <p>Is this confirms that Rails successfully connected to Postgres? How to simply check it?</p>
  
  <p>If yes - how long will I be able to use similar Postgres versions with Rails 4.2.8?</p>
  
  <p>Interesting thing that I didn't get similar messages with very similar setup so I wanted to be sure that I will be able to use this setup well.</p>
  
  <p>Many Thanks</p>