Abstract base class model vs Proxy model in Django

萝らか妹 提交于 2019-12-04 11:39:27

Nobody's touched this for 8 months. I should know better, but I'm going to take a stab at it.

Your first option, obviously, is to not use base classes at all and duplicate your Fields on each model. I know you didn't ask about this, but for others looking at this post, it is a good way to go for beginners. It's easy, and everything for the model is listed in one place rather than pointing to another model located somewhere else in the code for some of your fields.

Abstract base classes are probably the next easiest and next most commonly used. When you have a lot of duplication of fields across two or more models it is worth considering. Using this method you can eliminate the need to type (or cut and paste) fields over and over across multiple models. When you declare the base class abstract, the table is never actually built in the database. The base class is only used when the child tables are built. This keeps your database simpler and maintains performance because you don't have to build relationships to the base class and use joins to query data. You can also add additional fields (attributes) to the child classes on each of your child models(which proxy models cannot).

Proxy models are somewhat similar in that you have a base or parent class, but there are significant differences from there. You will use proxy models in situations where all of you models have the same fields (attributes), but you might have different "types" of objects. For instance you might have a base class of Cars, and use the manufacturer as your type. Then you may have Ford, Chevy and Honda models that are all proxy models of Cars. They all have the same fields. The manager class chosen for the model is what really makes them different from each other. From a database perspective, really only one table is built... Cars, leading to better performance than building multiple tables, but the drawback is you can't add manufactures-specific fields to the model without adding them to the entire Cars table.

In general I would recommend starting with Abstract Base Classes for models with lots of duplicate fields. Proxy models seem to be a more specific use case, but can be used as well if you have the use case and once you're more well-versed.

I'm not 100% clear on your specific use case based on your description, but hopefully I've given you enough information to decide what's best on your own.

易学教程内所有资源均来自网络或用户发布的内容,如有违反法律规定的内容欢迎反馈
该文章没有解决你所遇到的问题?点击提问,说说你的问题,让更多的人一起探讨吧!