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：我只是一个程序员，只有兴趣爱好），并计划使用Django直到我打了这个标签。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办法，无论是通过另一个Web框架（仅适用于Python），还是建议对模型进行更改，以便与Django的限制一起使用？我真的希望后者，因为我希望以此作为学习Django的机会。

示例：
表一有part_number和part_revision为应包括主键的两个字段。 P / N可以存在多个修订版本，但P / N + rev是唯一的。

表二以part_number，part_revision和dimension_number为主键。特定转速的P / N可以有多个维度，但是每个维度都是独一无二的。此外，在这种情况下，P / N + rev应该是表1的ForeignKey。

解决方案

一个代理键（一个自动增量列）作为主键列，并在您的域复合键上放置一个唯一的索引。

外键然后将引用代理主键列。

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.

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.

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.

解决方案

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.

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

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