Question

我正在尝试使用models.ImageField(upload_to=upload_location)

上传图片

def upload_location(instance,filename):
    print("%s/%s"%(instance.id,filename))
    return "%s/%s" %(instance.id,filename)

但是给予"GET /media/None/image_qacfEsv.jpg HTTP/1.1" 我尝试过使用slug字段它工作正常，但id和pk都没有工作我想使用obj ID为图像命名文件夹，但在id属性中给出none 这是我的文件

    def upload_location(instance,filename):
    print("%s/%s"%(instance.id,filename))
    return "%s/%s"%(instance.id,filename)

class Post(models.Model):
    draft = models.BooleanField(default=False)
    publish = models.DateField(auto_now=False,auto_now_add=False)
    user = models.ForeignKey(settings.AUTH_USER_MODEL,default=1)
    slug = models.SlugField(unique=True)
    title = models.CharField(max_length=120)
    image = models.ImageField(upload_to=upload_location,
                          null=True,blank=True,
                          width_field="width_field",
                          height_field="height_field")
    height_field = models.IntegerField(default=0)
    width_field = models.IntegerField(default=0)
    content = models.TextField()
    updated = models.DateTimeField(auto_now=True, auto_now_add=False)
    timestamp = models.DateTimeField(auto_now=False, auto_now_add=True)

Answer 1

在保存对象之前无法获取pk - 实际上检查对象是否有pk是检查它是否已保存的好方法。

相反，我建议在模型上添加UUID字段。类似的东西：

import uuid

class Post(models.Model):
    uuid = models.UUIDField(default=uuid.uuid4, editable=False, unique=True)
    ...

uuid字段将是唯一的，并且在您创建对象时可用，因此您可以在上传路径中使用该字段。

Answer 2

我遇到了类似的问题，这就是我的做法。

def upload_location(instance, filename):
    #return "%s/%s.%s" %(instance.id, instance.id, extension)
    if not instance.id:
        Model = instance.__class__
        new_id=None
        try:
            new_id = Model.objects.order_by("id").last().id
            if new_id:
                new_id += 1
            else:
                pass
        except:
            new_id=1
    else:
        new_id = instance.id
    return "%s/%s/%s" %(Model.__name__, new_id, filename)

如何在保存实例之前获取django模型实例的pk

2 个答案: