考虑这样的情况，我试图为一家公司建模一个数据库:
- 实体:
Employees、Managers、Departments. -
Employee只在1Department中工作，而Department可能有很多Employees在其中工作. -
Manager可以仅管理1Department，类似地，Department可以仅具有1Manager. -
Manager可以管理多个Employees，而Employee只能管理一个Manager.
Now I have 2 ways to model this:个
100
我将考虑Manager个实体从Employee个实体继承，考虑到我将保留对管理者来说唯一的数据(例如， prize 和状态).
-
由于
Department和Employee之间的关系是1:N，那么我将把Department Id作为Works的Employee表中的外键 关系. -
由于
Department和Manager之间的关系是1:1，那么我将把Department Id作为Manages的Manager表中的外键 关系.
Problem: How can I represent the recursive relation between the 100 and 101?
100
I'll consider that the Manager entity is not needed as other Employees may also have a Bonus and Status. (Actually I added these 2 attributes just to see how to model it in both cases)
- 由于
Department和Employee之间的关系是1:N，那么我将把Department Id作为Works的Employee表中的外键 关系. - 既然
Employee和Manager之间的关系是1:N，那么我将把
Problem: How can I represent the relation between the 100 and 101?
问题:
- 这两种设计都有明显的错误吗？
- 如何解决这两种情况下的每个问题？
- 有比这两个更好的解决方案吗？
