Prefer the mysql2 gem for MySQL database.ymls

railties/lib/rails/generators/rails/app/templates/config/databases/mysql.yml

 # MySQL.  Versions 4.1 and 5.0 are recommended.
 #
 # Install the MySQL driver:
-#   gem install mysql
-# On Mac OS X:
-#   sudo gem install mysql -- --with-mysql-dir=/usr/local/mysql
-# On Mac OS X Leopard:
-#   sudo env ARCHFLAGS="-arch i386" gem install mysql -- --with-mysql-config=/usr/local/mysql/bin/mysql_config
-#       This sets the ARCHFLAGS environment variable to your native architecture
-# On Windows:
-#   gem install mysql
-#       Choose the win32 build.
-#       Install MySQL and put its /bin directory on your path.
+#   gem install mysql2
 #
 # And be sure to use new-style password hashing:
 #   http://dev.mysql.com/doc/refman/5.0/en/old-client.html
 development:
-  adapter: mysql
+  adapter: mysql2
   encoding: utf8
   reconnect: false
   database: <%= app_name %>_development
@@ -32,7 +23,7 @@ development:
 # re-generated from your development database when you run "rake".
 # Do not set this db to the same as development or production.
 test:
-  adapter: mysql
+  adapter: mysql2
   encoding: utf8
   reconnect: false
   database: <%= app_name %>_test
@@ -46,7 +37,7 @@ test:
 <% end -%>
 
 production:
-  adapter: mysql
+  adapter: mysql2
   encoding: utf8
   reconnect: false
   database: <%= app_name %>_production