[英]Question about E-R modelling
I've got the following business requirements for a scenario: 对于方案,我具有以下业务要求:
http://ompldr.org/vN2ZvdQ http://ompldr.org/vN2ZvdQ
and I came up with the following UML diagrams to model the relationship: 我想出了以下UML图来对这种关系进行建模:
http://ompldr.org/vN2Y5Yg http://ompldr.org/vN2Y5Yg
I was wondering whether I have successfully managed to implement all the relations in the ER model, especially the 1..* relationship. 我想知道我是否成功地实现了ER模型中的所有关系,尤其是1 .. *关系。 Furthermore, it is my understanding that mandatory relationships cannot be implemented just by using FK/PK so I have to add additional constraints, is that so?
此外,据我了解,强制性关系不能仅通过使用FK / PK来实现,因此我必须添加其他约束,是吗?
Its seems to be ok. 似乎还可以。 You can use ERWin or DBDesigner to doing your work in a easier way.
您可以使用ERWin或DBDesigner来更轻松地完成工作。 Consider
ON DELETE CASCADE, ON UPDATE CASCADE
, etc in your constraints. 在约束中考虑
ON DELETE CASCADE, ON UPDATE CASCADE
等。
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