如何更好的将数据库反映成对象? 如何更好的将对象的变化反映到数据库.? an employee constrains base information positon information e_base(id,name,age.....)e_position(id,name,memo...)e_base_position(id,base_id,position_id) class Base;class Position;class Employee(Base , Base_Position);{ addBase(); addPosition(); deleteBase();//if Position.isExits() can not delete; deletePosition(); destory() { deletePosition(); deleteBase(); }}