如何在 Django 模型中添加基于数组的文件

Question

I'm making an app atm where I get dummy data from a json file. My filed in this file looks like this:

 { "model": "card.model", "pk": 2222, "fields": { "meal_1": 5555, "meal_2": 5556, "meals": "[5555, 5556]" } } { "model": "meal.model", "pk": 5555, "fields": { "name": "Pizza", "vagan": True } } { "model": "meal.model", "pk": 5556, "fields": { "name": "Sandwich", "vagan": False } }

I have a Meal class that contains: name, photo, description. I have also Card class that gets info right from json file.

 class Card() { meal_1 = models.ForeignKey( Meal, related_name='meal_1" ) meal_2 = models.ForeignKey( Meal, related_name='meal_2" ) meals=[] ?? }

How can I add an array field that will contain a reference to these meals. What I want to achieve is loop over this meals and place into django template. Now I do this by reference to each filed: instance.meal_1.name... etc.

Answer 1

I think you could add Card as ForeignKey to your Meal class. Then in the template, you can loop for each Meal in the Card.

meal.py

class Meal(models.Model):
    ...
    card = models.ForeignKey(Card, on_delete=models.CASCADE)
    ...
    ...

template.html

{% for meal in card.meal_set %}
   {{ meal.name }}
{% endfor %}

Answer 2

I think Night Owl's approach is pretty good, but there is also another approach you can take. That is using ManyToManyField .

In the given JSON , id of meal_1 and meal_2 are inside meals field. So I don't think its necessary for you to consider meal_1 and meal_2 when creating models(because there could be more than 2 meals). So you can try to create ManyToMany Relation between Card and Meal . Like this:

class Meal(models.Model):
    name = models.CharField(max_length=255)
    vagan = models.BooleanField()

class Card(models.Model):
    meals = models.ManyToManyField(Meal)


# usage

   meal = Meal.objects.create(name="sandwitch", vegan=False)
   card = Card.objects.create()
   card.meals.add(meal)

# template

   {% for meal in card.meals.all %}
       {{ meal.name }}
       {{ meal.vegan }}
   {% endfor %}