关系模型基于谓词逻辑和集合论,为数据库管理提供了坚实的数学基础。
创新不仅仅是技术的问题,它关乎改变人们的思维和行动方式。
Live as if you were to die tomorrow. Learn as if you were to live forever.
Can a man still be brave if he’s afraid. That is the only time a man can be brave.
The past is always with us, shaping our present and our future.