How to query from 2 Models in Class based views in django? - django

Question

I have a model Log and another model Solutions and I am using DetailView to display details of each log
Each log can have many solutions.
There is a log field in the Solutions model that is Foreign Key to Log model..
Now how do I access both Log model and Solutions of that particular log in the same html template if I want to display all the solutions of that particular log below the details of the log
models.py:
class Log(models.Model):
title = models.CharField(blank=False, max_length=500)
content = models.TextField(blank=False)
created = models.DateTimeField(auto_now_add=True)
updated = models.DateTimeField(auto_now=True)
slug = models.SlugField(max_length=50, null=False, unique=True)
author = models.ForeignKey(User, on_delete=models.CASCADE,null=True, blank=True)
image = models.ImageField(
upload_to='images', blank=True)
def save(self, *args, **kwargs):
super().save()
self.slug = self.slug or slugify(self.title + '-' + str(self.id))
super().save(*args, **kwargs)
class Meta:
verbose_name = ("Log")
verbose_name_plural = ("Logs")
def __str__(self):
return f"{self.title}"
def get_absolute_url(self):
return reverse("log-detail", kwargs={"question": self.slug})
class Solutions(models.Model):
log = models.ForeignKey(
Log, on_delete=models.CASCADE, blank=True, null=True)
author = models.ForeignKey(User, on_delete=models.CASCADE,null=True, blank=True)
solution = models.TextField(null=True)
created = models.DateTimeField(auto_now_add=True)
updated = models.DateTimeField(auto_now=True)
slug = models.SlugField(max_length=50, null=False, blank=True)
image = models.ImageField(
upload_to='images', blank=True)
def save(self, *args, **kwargs):
self.slug = self.slug or slugify(self.solution)
super().save(*args, **kwargs)
class Meta:
verbose_name = ("Solution")
verbose_name_plural = ("Solutions")
def __str__(self):
return f" {self.solution} "
views.py:
class LogDetailView(DetailView):
model = Log
slug_url_kwarg = 'question'
slug_field = 'slug'
log_detail.html:
{% extends 'log/base.html' %}
{%load crispy_forms_tags %}
{% block content %}
<title>Error Logger - {{object.title}}</title>
<div class="main container mt-4 p-3 mb-4">
<img style='display:inline;' class='rounded-circle account-img' src="{{ object.author.profile.avatar.url }}" alt="">
<h1 style='display:inline;'>
{{ object.title }}
</h1>
<p>Author: {{ object.author }}</p>
<p>Date and time of creation: {{ object.created }}</p>
<span> Details </span>:
<p class="big ml-4">{{ object.content }} <br />
{% if object.image %}
<img style="width: 20vw" class="mt-4" src="{{ object.image.url }}" alt="image" />
{% else %}
{% endif %}
</p>
</div>
<br />
<a
class="btn btn-outline btn-info button-solution"
href="#"
>Add solution</a
>

Answer 1

You can enumerate over these in the template by accessing the relation in reverse, this is normally modelname_set, unless you set a related_name=…. So in this case it is solutions_set:
{% for solution in object.solutions_set.all %}
{{ solution }}
{% endfor %}
If the ForeignKey has a related_name=… [Django-doc], for example with:
class Solutions(models.Model):
log = models.ForeignKey(
Log,
on_delete=models.CASCADE,
blank=True,
null=True,
related_name='solutions'
)
# …
Then we access this with:
{% for solution in object.solutions.all %}
{{ solution }}
{% endfor %}
Note: normally a Django model is given a singular name, so Solution instead of Solutions.