循环遍历两个包含列表并连接的模型 Django

Question

我是 Python/Django 的初学者，我目前正在尝试制作一个用于制作收集日志的基本应用程序。首先，用户选择一个类别，然后在该类别下插入对象。

我在 models.py 中有两个类，代码如下：

class object_category(models.Model):
"""This class contains the users different categories"""
CATEGORY_CHOICES = [
    ('category1', 'category1'),
    ('category2', 'category2'),
    ('category3', 'category3'),
]
"""Plural for multiple categories"""
class Meta:
    verbose_name_plural = 'Categories'
    
"""Returns the above stated choices"""
category = models.CharField(max_length=50, choices=CATEGORY_CHOICES)
def __str__(self):
    return self.category

class object_name(models.Model):
"""This class contains the object name that is housed within a certain category"""
"""Links the object to one of the chosen categories"""
category = models.ForeignKey(object_category, on_delete=models.CASCADE)

# Placeholder for connection with a plant database API
object = models.CharField(max_length=50)

"""Return the object input from the user"""
def __str__(self):
    return self.object

这里是views.py代码：

def collection(request):
"""The page that opens the collection of objects"""
object_category = Object_category.objects.order_by('category')
object_name = Object_name.objects.order_by('object')

context = {
    'object_category': object_category,
    'object_name': object_name
}

return render(request, 'plntz_main/collection.html', context)

最后这是我的 html 文档代码：

{% for category in object_category %}
    {% for object in object_name %}
        <h3>{{ category }}</h3>
            <li>{{ object }}</li>
{% empty %}
    <li>No category has been added yet.</li>
    {% endfor %}
{% endfor %}

这会显示类别和对象，但它们没有链接。

我要显示的是：

• 用户选择的类别
• 该特定类别中的每个对象

谁能解释我是如何修改代码得到这个结果的？

对不起，这是一团糟。我是新手，这是我第一次尝试一个项目，也是我在 stackoverflow 上的第一个问题。

谢谢！

Answer 1

您应该先阅读文档并逐步完成一些基本教程，在此处阅读有关过滤查询集Django Querysets 的文档。

你可以这样做来实现它

首先，将related_name 设置为您的类别外键

class object_name(models.Model):
"""This class contains the object name that is housed within a certain category"""
"""Links the object to one of the chosen categories"""
category = models.ForeignKey(object_category, on_delete=models.CASCADE, related_name='object_names')

# Placeholder for connection with a plant database API
object = models.CharField(max_length=50')

"""Return the object input from the user"""
def __str__(self):
    return self.object

然后在你的views.py中你只需要这样做

object_categories = Object_category.objects.all().order_by('category')

context = {
    'object_categories': object_categories,
}

然后我你的模板文件做这样的事情：

    {% for category in object_categories %}
        <h3>{{ category }}</h3>
        {% for name in object_categories.object_names.all %}
                <li>{{ name.object }}</li>
        {% endfor %}
    {% empty %}
        <li>No category has been added yet.</li>
    {% endfor %}

我没有测试，你自己试试看是否有效:)