如何为广义 class 图创建 table？

Question

我正在开发一个在线求职门户网站。在 class 图中，我将雇主和雇员概括为成员 class 并且我将 'MID' 作为主键。现在我很困惑如何为 Employer & Employee 创建表？

Answer 1

这是您需要的表格：

Member
========
Id (or MId) (PK)
... (Specifications you need)

Employer
========
Id (PK)
MId (FK to Member table)
... (Specifications you need)

Employee
========
Id (PK)
MId (FK to Member table)
EId (FK to Employer table)
... (Specifications you need)