rails3中mysql2的安装

rails3中默认的mysql适配器是mysql2，执行以下命令进行安装：

 

gem install mysql2

 

结果报出以下错误信息：

 

ERROR:  Error installing mysql2:
        The 'mysql2' native gem requires installed build tools.

 

Please update your PATH to include build tools or download the DevK
from 'http://rubyinstaller.org/downloads' and follow the instructio
at 'http://github.com/oneclick/rubyinstaller/wiki/Development-Kit'

 

最终，通过以下命令成功安装：

 

gem install mysql2 -v 0.2.6 --platform x86-mingw32

 

注意：如果rails版本<3.1.0，就安装mysql 0.2.6，如果rails版本是3.1.*，才需要安装mysql 0.3.*。