django - 在 Django 查询中过滤 related_set

Question

class Hardware(models.Model):
    date = models.PositiveSmallIntegerField()
    node = models.ForeignKey('Node', on_delete=models.CASCADE,null = True)
    slot = models.PositiveSmallIntegerField(null = True)
    server = models.CharField(max_length=20,null = True)
    server_state = models.CharField(max_length=20,null = True)
    adapter = models.CharField(max_length=20,null = True)
    adapter_state = models.CharField(max_length=20,null = True)

    class Meta:
        unique_together = ('date', 'node','slot')
        order_with_respect_to = 'node'

    def __str__(self):
        return self.node.name +" " + self.server

class Node(models.Model):
    name = models.CharField(max_length = 40, primary_key = True)
    def __str__(self):
        return self.name

def inventory_by_node(request):
    day = (arrow.now().day) - 1
    nodes = Node.objects.prefetch_related("hardware_set").all()
    return render(request, 'automation/inventory_by_node.html',{'nodes':nodes})

我需要根据等于当前日期的日期过滤硬件集。我试过了

nodes = Node.objects.prefetch_related(Prefetch("hardwares", quesryset=Hardware.objects.filter(date=day)).all() 

但是它不起作用，说没有定义 Prech

Answer 1

试试这个:

prefetch = Prefetch("hardware_set", queryset=Hardware.objects.filter(date=day))
nodes = Node.objects.prefetch_related(prefetch).all()