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在Django的N.annotate()创建的田地上使用.extra()
原标题:Using .extra() on fields created by .annotate() in Django

我想在表格中为每个物体提取两个领域(即总合)。

下面可以描述一个比照的比照,但可在<代码>上产生。 外地名单不明栏目:-Error:

items = MyModel.objects.annotate(
                field1=Sum("relatedModel__someField"),
                field2=Sum("relatedModel__someField")).extra(
                        select={"sum_field1_field2": "field1 + field2"})

我也试图利用F()进行实地调查,但这使我无法作q的发言。

任何关于如何解决这一问题的想法都受到高度赞赏。

最佳回答

这是你们想要的吗?

items = MyModel.objects.extra(
    select = { sum_field1_field2 :  SUM(relatedModel__someField) + SUM(relatedModel__someField) },
)
问题回答

为了让许多或许多到一个(反常)的关系发挥作用,你可以采取以下措施:

items = MyModel.objects.extra(
    select = { sum_field1_field2 :  SUM("relatedModel"."someField") + SUM("relatedModel"."someField") },
      )

但是,如果你需要另一个说明,如计算,这也会中断,因为额外增加按条款向小组陈述,而此处不允许合并职能。





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