Missing Gem called "rails"?? Very confused

I'm trying to run a rake db:create

And get the following message:

Could not find gem '开发者_JS百科rails (= 3.0.10, runtime)' in any of the gem sources listed in your Gemfile. Run bundle install to install missing gems.

I'm brand new to Rails and have no idea what I'm doing so any help is very appreciate.

Thanks!

Go to your console and run

bundle install

you may need to

sudo bundle install.

If you check the Gemfile of your application <APPLICATION_ROOT>/Gemfile, you should see something like

source 'http://rubygems.org'
gem 'rails', '3.0.10'
...

When you run bundle install, it grabs all the gems you have listed in your Gemfile to make sure you can run your application.

If you get an error trying to run bundle install or sudo bundle install, first run gem install bundler or sudo gem install bundler.

Whether or not you need the sudo will depend on how your ruby installation is set up.

EDIT: Problem appears to be related to ruby versioning issues (go figure!), I've suggested that he install RVM or an easier to read guide for mac