uninitialized constant MysqlCompat::MysqlRes (using mms2r gem)

Question

moved a rails app of mine onto a new server and had to install a few gem dependencies. However, after installing the mysql gem I get the error, uninitialized constant Mysql

Answer 1

The mysql and mysql2 gems both work on ruby 1.9.2 just update ruby and install the gem you need.

Answer 2

How is the mysql dependency related to mms2r? I'm the mms2r author, btw.

The mms2r gemspec https://github.com/monde/mms2r/blob/master/mms2r.gemspec does not list a mysql dependency.

Answer 3

gem uninstall mysql

gem install mysql -v 2.7 -- --with-mysql-config=/usr/local/mysql/bin/mysql_config

ldconfig /usr/local/mysql/lib/mysql

RAILS_ENV=production rake db:migrate --trace

This worked for me.

Answer 4

If your Mysql version is 5.5 you should uninstall it. I just left an article about using mysql with ruby : http://geryit.com/blog/2011/01/installing-mysql-with-rails-on-mac-os-x-snow-leopard/

Answer 5

I had the same problem after upgrading from Fedora 10 to Fedora 12. I fixed it by just uninstalling mysql gem and installing it again. So it complies with the new version of MySQL.

Answer 6

On Mac OS X 10.6.4, I had to specify the architecture and config directory:

sudo env ARCHFLAGS="-arch x86_64" gem install mysql -- --with-mysql-config=/usr/local/mysql/bin/mysql_config