I have just updated my MacBook to Mountain Lion. Since then, my MAMP installation does not work properly so I decided to use the build httpd/php stuff. For this, I have additionally installed a new mysql server (following this tutorial). Everything runs very well. Now my question is, how to use my old databases in my new server? I tried to create a new database which creates a folder "databasename". Into this folder I moved all the .frm files, corrected rights and owner and started mysql, but unfortunately, phpmyadmin does not recognize the tables... did I something wrong? Alternatively, I would just set the data directory of the new mysql server to my old directory, but I cannot find the my.cnf file :-( Where is it stored?
The best thing to do is to export the databases from the MAMP server and import them to your new database server.
Here's a guide with MySQL dump and restore: http://www.patrickpatoray.com/?Page=30