我如何在 Django 中查询评论

Question

我是 Django 的新手，我一直在关注在线教程。我在如何显示评论方面遇到问题。我如何查询视图中的评论，以便我可以显示特定 post.

的评论

型号：

class Post(models.Model):
    poster_profile = models.ForeignKey(settings.AUTH_USER_MODEL,on_delete=models.CASCADE, blank=True,null=True)
    image_caption = models.TextField(blank=True, null=True)

class Comments (models.Model):
    user = models.ForeignKey(settings.AUTH_USER_MODEL,on_delete=models.CASCADE, blank=True,null=True)
    commented_image = models.ForeignKey(Post, on_delete=models.CASCADE, null=True, blank=True)
    comment_post = models.TextField()

Views.py:

def home_view(request):
    comment = Comments.objects.all() #This is getting all comment in all post, how do i query for comment in a particular post.
    context{'comment':comment}
    return render(...)

模板：

{% for com in comment %}
<p>{{ com.comment_post }}</p>
{% endfor %}

Answer 1

你可以做到

post = Post.objects.get(id=1)
comment = post.comments_set.all()

Following Relationships "Backward"

If a model has a ForeignKey, instances of the foreign-key model will have access to a Manager that returns all instances of the first model. By default, this Manager is named FOO_set, where FOO is the source model name, lowercased. This Manager returns QuerySets, which can be filtered and manipulated as described in the “Retrieving objects” section above.

请注意，此行为可以被覆盖。

You can override the FOO_set name by setting the related_name parameter in the ForeignKey definition. For example, if the Entry model was altered to blog = ForeignKey(Blog, on_delete=models.CASCADE, related_name='entries'), the above example code would look like this:

编辑#2：

views.py:

def home_view(request):
    posts = Post.objects.all().reverse()[5]

    context{ 'posts': posts, }
    return render(...)

现在在您的模板中，您可以执行以下操作：

{% if posts %}
{% for post in posts %}
    {{ post.image_caption }}


    {% for comment in post.comments_set.all %}
        {{ comment.comment_post }}
    {% endfor %}

{% endfor %}
{% endif %}

Answer 2

def home_view(request):
particular_Post= Post.objects.get(id=1)
    comment = Comments.objects.get(Post=particular_Post)
context{'comment':comment}
return render(...)

为了理解 Django 中的查询，我建议你从

开始

python manage.py shell

并导入您的模型

Answer 3

首先，查看 Django 查询集文档，尤其是 select_related 此类问题（以减少对数据库的查询次数）。我没有尝试，但下面的代码片段一定有效。

class Post(models.Model):
    poster_profile = models.ForeignKey(settings.AUTH_USER_MODEL,on_delete=models.CASCADE)
    image_caption = models.TextField(blank=True, null=True)

class Comments (models.Model):
    user = models.ForeignKey(settings.AUTH_USER_MODEL,on_delete=models.CASCADE)
    commented_image = models.ForeignKey(Post, related_nam="comments", on_delete=models.CASCADE)
    comment_post = models.TextField()

...

def home_view(request):
    post = Post.objects.filter(id=request.data.get('post_id')).select_related("comments") # specify the post anyhow ..
    comments = post.comments
    context{'comment': comments}
    return render(...)

我如何在 Django 中查询评论

How do i query for comment in Django

python

django

django-queryset