主要是用Dtree.js做的一个树形结构，有利于大家都学习和共同进步。用到了数据库，主要有Student和Class两张表，通过Class可以动态的获得Student的信息-Dtree.js is mainly used to do a tree structure is conducive to all learning and common progress. Use a database, there are Student and Class 2 form, through the Cl