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这是我正在创建的一个简单的博客应用程序。我有一个模型可以创建一篇文章并为每篇文章生成一个 UUID。这按预期工作。

我现在正在尝试从我的模型“Post”中创建一个包含“post_id”对象的视图变量，以便以后可以将此变量插入到我的 html 模板中。令人困惑的是，我知道 Post 模型生成了一个有效的 UUID（至少我对 UUID 的理解），因为我已经看到它生成了，所以我不清楚从哪里开始寻找解决这个问题。网上的其他类似问题似乎与我的问题无关。

我的应用程序/views.py

from django.shortcuts import render
from django.utils import timezone
from .models import Post

def blog_list(request):
    posts = Post.objects.filter(published_date__lte=timezone.now()).order_by('published_date')
    post_uid = Post.objects.get(pk="post_id")

    context = {
        "post_uid": post_uid,
        "posts": posts
            }

    return render(request, 'blog/blog_list.html', context)


def article(request, post_id):
    current_article = Post.objects.get(pk=post_id)
    return render(request, 'blog/article.html', {'current_article':current_article})

我的应用程序/模型.py

from django.db import models
from django.conf import settings
from django.utils import timezone
import uuid


class Post(models.Model):
    author = models.ForeignKey(settings.AUTH_USER_MODEL, on_delete=models.CASCADE)
    title = models.CharField(max_length=200)
    text = models.TextField()
    created_date = models.DateTimeField(default=timezone.now)
    published_date = models.DateTimeField(blank=True, null=True)
    post_id = models.UUIDField(primary_key=True, default=uuid.uuid4, editable=False)

    def publish(self):
        self.published_date = timezone.now()
        self.save()

    def __str__(self):
        return self.title

返回的错误

Internal Server Error: /blog/
Traceback (most recent call last):
  File "/home/taylor/tc_site/virtualenv/lib/python3.8/site-packages/django/db/models/fields/__init__.py", line 2434, in to_python
    return uuid.UUID(**{input_form: value})
  File "/usr/lib/python3.8/uuid.py", line 171, in __init__
    raise ValueError('badly formed hexadecimal UUID string')
ValueError: badly formed hexadecimal UUID string

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/home/taylor/tc_site/virtualenv/lib/python3.8/site-packages/django/core/handlers/exception.py", line 47, in inner
    response = get_response(request)
  File "/home/taylor/tc_site/virtualenv/lib/python3.8/site-packages/django/core/handlers/base.py", line 181, in _get_response
    response = wrapped_callback(request, *callback_args, **callback_kwargs)
  File "/home/taylor/tc_site/blog/views.py", line 7, in blog_list
    post_uid = Post.objects.get(pk="post_id")
  File "/home/taylor/tc_site/virtualenv/lib/python3.8/site-packages/django/db/models/manager.py", line 85, in manager_method
    return getattr(self.get_queryset(), name)(*args, **kwargs)
  File "/home/taylor/tc_site/virtualenv/lib/python3.8/site-packages/django/db/models/query.py", line 424, in get
    clone = self._chain() if self.query.combinator else self.filter(*args, **kwargs)
  File "/home/taylor/tc_site/virtualenv/lib/python3.8/site-packages/django/db/models/query.py", line 941, in filter
    return self._filter_or_exclude(False, args, kwargs)
  File "/home/taylor/tc_site/virtualenv/lib/python3.8/site-packages/django/db/models/query.py", line 961, in _filter_or_exclude
    clone._filter_or_exclude_inplace(negate, args, kwargs)
  File "/home/taylor/tc_site/virtualenv/lib/python3.8/site-packages/django/db/models/query.py", line 968, in _filter_or_exclude_inplace
    self._query.add_q(Q(*args, **kwargs))
  File "/home/taylor/tc_site/virtualenv/lib/python3.8/site-packages/django/db/models/sql/query.py", line 1393, in add_q
    clause, _ = self._add_q(q_object, self.used_aliases)
  File "/home/taylor/tc_site/virtualenv/lib/python3.8/site-packages/django/db/models/sql/query.py", line 1412, in _add_q
    child_clause, needed_inner = self.build_filter(
  File "/home/taylor/tc_site/virtualenv/lib/python3.8/site-packages/django/db/models/sql/query.py", line 1347, in build_filter
    condition = self.build_lookup(lookups, col, value)
  File "/home/taylor/tc_site/virtualenv/lib/python3.8/site-packages/django/db/models/sql/query.py", line 1193, in build_lookup
    lookup = lookup_class(lhs, rhs)
  File "/home/taylor/tc_site/virtualenv/lib/python3.8/site-packages/django/db/models/lookups.py", line 25, in __init__
    self.rhs = self.get_prep_lookup()
  File "/home/taylor/tc_site/virtualenv/lib/python3.8/site-packages/django/db/models/lookups.py", line 77, in get_prep_lookup
    return self.lhs.output_field.get_prep_value(self.rhs)
  File "/home/taylor/tc_site/virtualenv/lib/python3.8/site-packages/django/db/models/fields/__init__.py", line 2418, in get_prep_value
    return self.to_python(value)
  File "/home/taylor/tc_site/virtualenv/lib/python3.8/site-packages/django/db/models/fields/__init__.py", line 2436, in to_python
    raise exceptions.ValidationError(
django.core.exceptions.ValidationError: ['“post_id” is not a valid UUID.']

此外，如果它很有价值 - 添加 post_id 对象时的最新迁移文件。

myapp/migrations/0002_auto_20210830_1450.py

from django.db import migrations, models
import uuid

def create_uuid(apps, schema_editor):
    Post = apps.get_model('blog', 'Post')
    for x in Post.objects.all():
        x.post_id = uuid.uuid4()
        x.save()


class Migration(migrations.Migration):

    dependencies = [
        ('blog', '0001_initial'),
    ]

    operations = [
        migrations.RemoveField(
            model_name='post',
            name='id',
        ),
        migrations.AddField(
            model_name='post',
            name='post_id',
            field=models.UUIDField(blank=True, null=True),
        ),
        migrations.RunPython(create_uuid),
        migrations.AlterField(
            model_name='post',
            name='post_id',
            field=models.UUIDField(default=uuid.uuid4, unique=True)
        )
    ]
4

1 回答 1

1

您的查询看起来不对。您在 post_id 周围使用了引号

post_uid = Post.objects.get(pk="post_id")

试试这个而不是上面不带引号的：

post_uid = Post.objects.get(pk=post_id)

blog_list您的方法中也没有 post_id 参数。您需要将post_id参数传递给此方法。

于 2021-08-31T22:12:18.117 回答