Django 或类似的复合主键 [英] Django or similar for composite primary keys

问题描述

我正在为我的工程公司编写一个 Web 应用程序(警告:我只是业余爱好的程序员)并计划使用 Django，直到我遇到这个障碍.我想使用的模型自然有多列主键.根据 http://code.djangoproject.com/ticket/373，我不能使用 Django，至少不是发布版本.任何人都可以帮助我解决方法，无论是通过另一个 Web 框架(请仅基于 Python)还是建议对模型进行更改，以便它可以与 Django 的限制一起使用?我真的希望是后者，因为我希望借此机会学习 Django.

I am writing a web application for my engineering company (warning: I am a programmer only by hobby) and was planning on using Django until I hit this snag. The models I want to use naturally have multi-column primary keys. Per http://code.djangoproject.com/ticket/373, I can't use Django, at least not a released version. Can anyone help me with a workaround, whether it be via another web framework (Python-based only, please) or by suggesting changes to the model so it will work with Django's limitations? I am really hoping for the latter, as I was hoping to use this as an opportunity to learn Django.

示例:表一有 part_number 和 part_revision 作为两个字段，应该包含一个主键.一个 P/N 可以存在于多个修订版中，但 P/N + rev 是唯一的.

Example: Table one has part_number and part_revision as two fields that should comprise a primary key. A P/N can exist at multiple revisions, but P/N + rev are unique.

表二以part_number、part_revision和dimension_number为主键.特定转速下的 P/N 可以有多个维度，但是，每个维度都是唯一的.另外，在这种情况下，P/N + rev 应该是表一的外键.

Table two has part_number, part_revision and dimension_number as its primary key. A P/N at a specific rev can have a number of dimensions, however, each is unique. Also, in this case, P/N + rev should be a ForeignKey of Table one.

推荐答案

一种解决方法是创建一个代理键(一个自动递增列)作为主键列，并在域复合键上放置一个唯一索引.

A work around is to create a surrogate key (an auto increment column) as the primary key column and place a unique index on your domain composite key.

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外键将引用代理主键列.

Foreign keys will then refer to the surrogate primary key column.

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