Web数据库的数据模型问题 [英] Data model problem for web database

问题描述

大家好，

我会说那些东西的新手，我希望我能在正确的论坛上。

I`m a newbie at that stuff I would say and I hope I`m at the right forum.

我想建立一个网络数据库（主题： 设备调查发明）。我有关于设备本身的数据然后我有关于设备位置的数据（在这种情况下在一个特定的建筑物中：我会把那个位置表放到
两个因为有城市，区，buildingno所以有可能有2个或更多的建筑物没有100，但他们在两个不同的城市）并且有一个所有者和一个维修公司。同一家公司可以同时成为所有者和维修者。并且
也有那些公司的联系人（带有电话号码和电子邮件）。

I want to build a web database (theme: equipment survey inventury). I`m having data about the equipment itsself and then I have data about the location of the equipment (in a specific building at this case: I would slip that location table into two because there are city, district, buildingno. So it is possible that there are 2 or more building with No 100 but they are in two different citys) and there are a owner and a repair company. Same company could be owner and repairer at the same time. And there are also a contact at that companies (with telephone number and email).

我会有一个tblEquipment和tblCity（带有来自Id的"联结"表）设备和来自城市的Id），tblBldg。所有公司在一个表中或两个单独的表中更好？

I would have a tblEquipment and tblCity (with a "junction" table with Id from equipment and Id from city), tblBldg. All companies in one table or better in two separate ones?

我感谢对该问题的任何评论或提示！抱歉我的英语很差！

I appreciate any comment or tip on that issue! And sorry for my poor english!

推荐答案

我认为你几乎是对的跟踪。

I think you are pretty much the right track.

>>您需要问的一些问题......公司只有一个联系人吗？ （如果是，那么联系方式会在公司表格中找到。如果公司可以有多个联系人，则需要联系表）

>> Some questions you need to ask...will a company have only one contact? (If yes, then the contact details go in the company table. If a company can have more than on econtact you need a contact table)

>>每件设备只有一个维修人员或拥有者吗？ （如果答案是一件设备可以有多个维修者所有者，则可能需要另外两个连接表......）

>> Will each piece of equipment have only one repairer or owner? (If the answer is a piece of equipment can have more than one repairer owner, you may need to two more junction tables...)

>>如果设备可以有一个不同的所有者和一个维修人员 - 在设备表中包含表中所有者ID和维修人员ID的字段。这两个字段都可以加入公司表格中的不同行。 当您创建
a查询时，您需要将公司表拖放到查询中两次 - 并为每个实例提供一个别名，如Repair Company和Owner Company。

>> If the equipment can have one different owner and one repairer - include in the equipment table a field for owner id and repairer id in the table. Both fields can join to different rows in the company table.  When you create a query, you need to drag and drop the company table into the query twice - and give each instance an alias like Repair Company and Owner Company.

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