我有模型,其实例每小时创建一次:
class Entry(models.Model):
class Meta:
ordering = ['time']
time = models.DateTimeField()
no2 = models.FloatField()
co = models.FloatField()
humidity = models.FloatField()
temperature = models.FloatField()
我想获得上个月几天的平均值,例如 30 个包含每天平均值的实例。如何实现?现在我写了这个方法:
def average_for_period(self, start, end):
entries_for_period = Entry.objects.filter(time__gte=start, time__lte=end)
average_value = entries_for_period.aggregate(Avg('temperature'), Avg('no2'), Avg('co'), Avg('humidity'))
return Entry(**average_value)
我应该怎么做才能实现功能?