Data migration 是指数据库数据变化的过程。
数据的哪些变化需要关注？
- A new member is added
- A member is removed
- A member is renamed
- The type of a member is changed
- The representation of a member is changed
数据迁移工具的实现
- 了解下 Django Migration 的机制，看它覆盖了上述哪些数据变化
- 找到脱离框架（比如 Django）的，维护数据变化的工具