Please install the mysql2 adapter: `gem install activerecord-mysql2-adapter`

环境： linux  ruby1.9.2   rails 3.0.5   mysql2 0.3.2

遇到问题：Please install the mysql2 adapter: `gem install activerecord-mysql2-adapter`

解决方法:

gem uninstall mysql2

 then

gem install mysql2 -v 0.2.7

参考：http://stackoverflow.com/questions/5840742/version-of-mysql2-0-3-2-doesnt-ship-with-the-activerecord-adapter-bundled-anym

“The problem is because you are trying to install the lastet version of mysql2 wich is incompatible with rails 3.0.x version ”

做ROR, 版本的问题 真让人头疼