Python-сообщество

 class Unit(models.Model):
    id_unit = models.AutoField(primary_key=True)
    device = models.ForeignKey(Device,on_delete=models.NOT_PROVIDED)
    vendor = models.ForeignKey(Vendor, on_delete=models.NOT_PROVIDED)
    model = models.ForeignKey(ModelsDev, on_delete=models.NOT_PROVIDED)
    serial_number = models.CharField(max_length=150, unique=True)
    description = models.TextField(null=True, blank=True)
    date_in = models.DateField(auto_now=True)
    cost = models.DecimalField(max_digits=10, decimal_places=2, default=0.00)
    component = models.BooleanField(default=False)

 class Repacking(models.Model):
    id_rep = models.AutoField(primary_key=True)
    unit = models.ForeignKey(Unit, on_delete=models.NOT_PROVIDED, related_name='dev')
    component = models.ForeignKey(Unit, on_delete=models.NOT_PROVIDED, related_name='comp')
    date_in = models.DateField(auto_now=True )