日活统计，代码暂存 activeUserCountPerDay.activeUserCount

    if isCreated:
        activeUserCountPerDay, isCreated = ActiveUserCountPerDay.objects.get_or_create(activeDate = date.today())
        activeUsers=ActiveUser.objects.all()#算是昨天的用户集合
        if isCreated:# and activeUsers第一次部署activeUsers为空，不检查就delete会出现exception
            activeUsers.delete()#是新建，则删除前一天的所有活跃用户
        activeUser.save()#是新来的就保存，则删除前一天的所有活跃用户
        activeUserCountPerDay.activeUserCount=len(activeUser.objects.all())
        activeUserCountPerDay.save()