Upgrade rails to GEM uninstall, and install a specified version of rails.

SlaveRailsUpgrade to GEM uninstall and gem cleanup
RecentRailsUpgrade from 1.1.6 to 1.2.1. If rails1.1.6 has been installed, how can this problem be solved?

1. Upgrade to 1.2.1 and retain 1.1.6
If you do not want to delete the previous version, first download the local installation package rails1.2.1
Http://bbs.railschina.com/thread-54-1-1.html
Run the gem install your. Gem command.
After the installation is complete, 1.2.1 and 1.1.6 coexist.

2. Upgrade to 1.2.1 and retain only the latest versions installed on the gem.
1. Use gem uninstall
First Delete the previous version, Gem uninstallRails
Install the new version.
2. Gem cleanup
After the installation is completed in the method 1, 1.2.1 and 1.1.6 coexist. to clear all installed older versions of gem, run
Gem cleanup
You can.

3. Install and uninstall a specified versionRails

Gem installRails-V version number

Gem uninstall-V version

4. Generate with the specified versionRailsProject:

RailsSpace _ version _ space project name