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作为学习 Python/Django 的一种方式，我正在尝试使用 PRAW 在 Django 中重新创建 reddit，但我遇到了一些问题。目前，我将我的应用程序配置为连接到 reddit 并从我的 IndexView 类的主页中检索前 10 个帖子，但是当我尝试在我的Posts模型中添加字段然后使用makemigrations. 即使我从 django admin 中删除了我的数据库中的所有内容，如果我在模型中添加一个字段，然后使用python manage.py makemigrations，我经常会收到一个错误提示no such column: post_is_self或类似内容。当我注释掉新字段时，重新启动 django 服务器，这些帖子又回到了数据库中，即使同时我还没有访问我的应用程序的索引。

我相信问题出在我填充数据库的方式上。当用户访问我的应用程序的索引时，我想检索最新的前 10 个帖子，但现在添加新字段非常困难。它似乎在不应该检索帖子时检索帖子，当将新字段添加到模型并调用 makemigrations 时，这会导致问题。

这是我的 IndexView 类：

class IndexView(generic.ListView):
    template_name = 'reddit/index.html'
    context_object_name = 'top_posts'

    #Get top 10 posts from the front page
    pp = pprint.PrettyPrinter(indent = 4)
    r = praw.Reddit(user_agent = user_agent)
    front_page = r.get_front_page(limit = thing_limit)
    for thing in front_page:
        # Format timestamp
        utc_dt = datetime.utcfromtimestamp(thing.created_utc).replace(
            tzinfo=pytz.utc
        )
        local_dt = local_tz.normalize(utc_dt.astimezone(local_tz))
        post = Post(
            id = thing.id,
            post_title = thing.title, 
            post_submitted_on = local_dt,
            post_upvotes = thing.ups,
            post_downvotes = thing.downs,
            post_score = thing.score,
            post_submitter = thing.author,
            post_comment_count = thing.num_comments,
            post_permalink = thing.permalink,
            post_url = thing.url,
            post_subreddit = thing.subreddit,
            post_subreddit_id = thing.subreddit_id,
            post_thumbnail = thing.thumbnail,
        )
        if thing.is_self:
            post.post_selftext = thing.selftext
        post.save()

    def get_queryset(self):
        # Return top 10 stories, in descending order by score
        return Post.objects.all().order_by('-post_score')[:10]

编辑：...和我的Post模型：

class Post(models.Model):
    def __unicode__(self):
        return self.post_title
    id = models.CharField(
        verbose_name='Post ID',
        primary_key=True,
        max_length=200
    )
    post_title = models.CharField(
        verbose_name='Post title',
        max_length=200
    )
    post_submitted_on = models.DateTimeField(
        verbose_name='Submitted on',
        null=True
    )
    post_upvotes = models.IntegerField(
        verbose_name='Upvotes',
        null=True
    )
    post_downvotes = models.IntegerField(
        verbose_name='Downvotes',
        null=True
    )
    post_score = models.IntegerField(
        verbose_name='Score',
        null=True
    )
    post_submitter = models.CharField(
        verbose_name='Submitted by',
        null=True,
        max_length=15
    )
    post_subreddit_id = models.CharField(
        verbose_name='Subreddit ID',
        null=True,
        max_length=200
    )
    post_comment_count = models.IntegerField(
        verbose_name='Number of comments', 
        null=True
    )
    post_permalink = models.URLField(
        verbose_name='Permalink',
        null=True
    )
    post_url = models.URLField(
        verbose_name='Post URL',
        null=True
    )
    post_subreddit = models.CharField(
        verbose_name='Subreddit',
        null=True,
        max_length=200
    )
    post_thumbnail = models.URLField(
        verbose_name='Thumbnail URL',
        null=True
    )
    #post_is_self = models.BooleanField(
    #   verbose_name='Is self post?',
    #   null=True,
    #   default=False
    #)
    post_selftext = models.TextField(
        verbose_name='Self post text',
        max_length=40000,
        default='Not a self post'
    )

我应该在其他地方检索热门帖子吗？是否在将新字段添加到模型之前检索帖子？任何帮助表示赞赏，谢谢！

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