5.5视图的作用视图可以隐藏的实现细节，保密级别较高的系统，数据库只对外提供相关的视图，java程序员只对视图对象进行CRUDmysql> create view myview2 as select empno a,ename b,sal c from emp_bak;Query OK, 0 rows affected (0.01 sec)mysql> select view2 fro