关于DAO操作是是连接数据库出现的问题
Exception in thread "main" java.lang.ClassNotFoundException: org.gjt.mm.mysql.Driver
at java.net.URLClassLoader$1.run(URLClassLoader.java:366)
at java.net.URLClassLoader$1.run(URLClassLoader.java:355)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:354)
at java.lang.ClassLoader.loadClass(ClassLoader.java:423)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308)
at java.lang.ClassLoader.loadClass(ClassLoader.java:356)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:186)
at database_demo.DatabaseConnection.<init>(DatabaseConnection.java:15)
at proxy.EmpDAOProxy.<init>(EmpDAOProxy.java:15)
at factory.DAOFactory.getIEmpDAOInstance(DAOFactory.java:8)
at dao.test.TestDAOInsert.main(TestDAOInsert.java:16)

出现了这个问题，求老鸟说明下这是什么意思？？

------解决方案--------------------
缺少数据库驱动jar包
------解决方案--------------------
打印sql语句