Question

所以我有这个模型：

class scoreShow(models.Model):
    dancer = models.ForeignKey(dancer)
    s1 = models.IntegerField(max_length = 2)
    s2 = models.IntegerField(max_length = 2)
    s3 = models.IntegerField(max_length = 2)
    s4 = models.IntegerField(max_length = 2)
    s5 = models.IntegerField(max_length = 2)
    s6 = models.IntegerField(max_length = 2)
    s7 = models.IntegerField(max_length = 2)
    counter = models.IntegerField(max_length = 2)
    stotal = models.IntegerField(max_length = 3)
    field_1 = models.IntegerField(max_length = 20, null=True, blank=True)
    field_2 = models.CharField(max_length = 20, null=True, blank=True)

    def __unicode__(self):
        return str(self.dancer)

从此视图表格中提供信息：

def scores(request):
     perf = dancer.objects.filter(perform=True)

     if request.method =='POST':
        intpk = request.POST.get("form")
        whendone = request.POST.get("done")

        contestant =dancer.objects.get(pk=intpk)

        showcase = inlineformset_factory(dancer, scoreShow, extra = 1)
        form = showcase(instance=None)

        if whendone == "save":

            form = showcase(request.POST, request.FILES, instance=contestant)
            if form.is_valid():
                form.save()

     return render_to_response("scores.html",locals(), context_instance = RequestContext(request))

它接受来自约13个人的1到10的数值。我需要计算13个人投入的平均分数。平均值为2个：

前7个类别的平均值。平均值s1，平均值s2＆amp;
所有S的平均值加在一起，因此平均s1总数+ s2总数...除以总条目数。 Ť

如果可能的话，我还想避免让任何人提交两次得分。任何人都可以帮我这个吗？

Answer 1

您可以通过以下方式使用Aggregation feature：

from django.db.models import Avg
qs = ScoreShow.objects.all()
return qs.aggregate(Avg('s1'), Avg('s2'), Avg('s3'), Avg('s4'), Avg('s5'), Avg('s6'),Avg('s7'))

或更短一些：

qs = ScoreShow.objects.all()
return qs.aggregate(*[Avg('s%d' % i) for i in range(1, 8)])

要计算所有分数的平均值，您需要将汇总与annotate结合使用：

from django.db.models import Avg, Sum
fields = ['s%d' % i for i in range(1,8)]
qs = ScoreShow.objects.annotate(sAll=Sum('id', field='+'.join(fields))).all()
return qs.aggregate(Avg('sAll'))

要确保没有人提交两个分数，请将unique=True添加到舞者外键：

class ScoreShow(models.Model):
    dancer = models.ForeignKey(dancer, unique=True)

如何计算django中这些条目的平均分数？

1 个答案: