Django-使用get_FOO_display进行聚合 [英] Django - aggregation with get_FOO_display

问题描述

请考虑以下内容：

status = queryset.values('status').annotate(count=Count('status'))

其中 status 字段是一个 CharField 和选择。这将产生具有 status DB值及其计数的字典列表。

where status field is a CharField with choices. This will result in a list of dictionaries with status DB value along with its count.

有没有办法汇总状态并显示其显示值？我已经查找了我可能可以模仿的 _get_FIELD_display 的代码，但是重复框架的内部代码有点。

Is there a way to aggregate status and show its display value instead? I have looked up the code of _get_FIELD_display which I probably can emulate, but it feels a tad hackish to repeat the framework's internal code.

推荐答案

如果不对SQL进行黑客攻击，您可能无法轻松地在DB级别上实现这一目标。但是，由于 get_FOO_display 在 Model 级别上运行，您甚至不必黑客 _get_FIELD_display 或手动查找选项（如果以下方法不会使您的服务器花费太多）：

Without hacking a SQL, you may not achieve this in DB level easily. But, since get_FOO_display operates on Model level, you don't even have to hack _get_FIELD_display or lookup in choices manually (If the following method does not cost your server too much):

YourModel(status=status).get_status_display()

因此

for s in queryset.values('status').annotate(count=Count('status')):
    print(queryset.model(status=s['status']).get_status_display())

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