django models implementing portion of hackerspaces space api

models.py

from django.db import models

class Status(models.Model):
    open = models.BooleanField()
    status = models.CharField(max_length=None)
    lastchange = models.DateTimeField() # needs to be longint

class Events(models.Model): # example is "fire-alarm"
    status = models.ForeignKey('Status')
    name = models.CharField(max_length=None)
    type = models.CharField(max_length=None)
    t = models.DateTimeField() # needs to be longint, time since epoch for event
    extra = models.TextField()

class Sensors(models.Model):
    status = models.OneToOneField('Status')

class Temp(models.Model):
    sensors = models.ForeignKey('Sensors')

class TempValue(models.Model):
    temp = models.ForeignKey('Temp')
    value = models.CharField(max_length=None) # matches ^[-+]?[0-9]+(.[0-9]+)?[FCK]$ 

class Feeds(models.Model):
    status = models.ForeignKey('Status')
    name = models.CharField(max_length=None)
    type = models.CharField(max_length=None) # mime-type, odd no django field for this
    url = models.URLField()