Mysql and git study resource

http://dev.mysql.com/tech-resources/articles/hierarchical-data.html

http://blog.xkoder.com/2008/08/13/git-tutorial-starting-with-git-using-just-10-commands/

http://www.linuxsir.org/main/doc/git/gittutorcn.htm

http://www.sqlteam.com/article/more-trees-hierarchies-in-sql