Django Rest Framework：更改查询集中带注释字段的输出格式

Question

你好 Whosebug 社区，

我目前正努力在 views.py 中指定输出格式。我有一列“日期”，它使用以下格式：2021-01-14。在我的回复中，我想更改日期格式，以便它只显示年份 2021.

我已经用 Cast 试过了，但似乎这不是正确的方法。对于这个视图，我不使用序列化器，因此添加它不会有一个选项。

views.py

class FilterParams(generics.ListAPIView):
    model = Variants
    queryset = Variants.objects.all()
    def get(self, request, *args, **kwargs):
        queryset = self.get_queryset()
        ModelsByYears = queryset.values('model').distinct().annotate(min_year=Min('date')).annotate(max_year=Max('date')).order_by('model')
        return Response(data= {'ModelsByYears':ModelsByYears})

我试过的：

class FilterParams(generics.ListAPIView):
    model = Variants
    queryset = Variants.objects.all()
    def get(self, request, *args, **kwargs):
        queryset = self.get_queryset()
        ModelsByYears = queryset.values('model').distinct().annotate(min_year=Min(Cast('date', DateTimeField(format="%Y")))).annotate(max_year=Max('date')).order_by('model')
        return Response(data= {'ModelsByYears':ModelsByYears})

错误信息

TypeError: __init__() got an unexpected keyword argument 'format'

Answer 1

您应该改用 Extract/ExtractYear 数据库函数

Takes an expression representing a DateField, DateTimeField, TimeField, or DurationField and a lookup_name, and returns the part of the date referenced by lookup_name as an IntegerField. Django usually uses the databases’ extract function, so you may use any lookup_name that your database supports.

Django Rest Framework：更改查询集中带注释字段的输出格式

Django Rest Framework: changing output format of annotated field in queryset

python

django

django-rest-framework

drf-queryset