Django中“ related_name”和“ related_query_name”属性之间的区别？ [英] Difference between 'related_name' and 'related_query_name' attributes in Django?

问题描述

您能解释Django中Field对象的 related_name 和 related_query_name 属性之间的区别吗？当我使用它们时，如何使用它们？谢谢！

Can you explain the difference between related_name and related_query_name attributes for the Field object in Django ? When I use them, How to use them? Thanks!

推荐答案

related_name 将是相关对象的属性，允许您向后转到带有外键的模型。例如，如果 ModelA 的字段类似于： model_b = ForeignKeyField（ModelB，related_name ='model_as'），则此字段将使您可以通过转到 model_b_instance访问与您的 ModelB 实例相关的 ModelA 实例.model_as.all（）。请注意，对于外键，这通常用复数形式编写，因为外键是一对多关系，并且该等式的多面是声明了外键字段的模型。

related_name will be the attribute of the related object that allows you to go 'backwards' to the model with the foreign key on it. For example, if ModelA has a field like: model_b = ForeignKeyField(ModelB, related_name='model_as'), this would enable you to access the ModelA instances that are related to your ModelB instance by going model_b_instance.model_as.all(). Note that this is generally written with a plural for a Foreign Key, because a foreign key is a one to many relationship, and the many side of that equation is the model with the Foreign Key field declared on it.

文档中链接的进一步说明很有帮助。 https://docs.djangoproject.com/en/ dev / topics / db / queries /＃backwards-related-objects

The further explanation linked to in the docs is helpful. https://docs.djangoproject.com/en/dev/topics/db/queries/#backwards-related-objects

related_query_name 在Django查询集中。它使您可以过滤与外键相关字段的反向关系。继续我们的示例-在 Model A 上有一个字段，例如：
model_b = ForeignKeyField（ModelB，related_query_name ='model_a'）将使您能够使用 model_a 作为查询集中的查找参数，例如： ModelB.objects.filter（model_a = whatever） 。 related_query_name 使用单数形式更为常见。正如文档所述，不必同时指定 related_name 和 related_query_name （或两者中的一个）。 Django有合理的默认值。

related_query_name is for use in Django querysets. It allows you to filter on the reverse relationship of a foreign key related field. To continue our example - having a field on Model A like: model_b = ForeignKeyField(ModelB, related_query_name='model_a') would enable you to use model_a as a lookup parameter in a queryset, like: ModelB.objects.filter(model_a=whatever). It is more common to use a singular form for the related_query_name. As the docs say, it isn't necessary to specify both (or either of) related_name and related_query_name. Django has sensible defaults.

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