python - 如何在 Django 中实现依赖下拉列表

Question

我有一个食品表，其中包含食品名称及其价格。每当用户从模板表单中选择食品时，与其关联的价格应自动显示在表单中。我该怎么做？？

models.py

class Food(models.Model):
    name = models.CharField(max_length = 100)
    price = models.IntegerField()

class Payment(models.Model):
    food = models.ForeignKey(Food, on_delete=models.CASCADE)

forms.py

class PaymentForm(forms.ModelForm):
    class Meta:
        model = Payment
        fields = '__all__'

views.py

def payment_details(request):
    amounts = Food.objects.all()

    context={
        'amounts' : amounts
            }


    return render(request, 'app_name/payment.html',context)

模板

<label>Select the Food</label>
     <select name="name" class="form-control" required>
           {% for amount in amounts %}
            <option value="{{amount.food.name}}">{{amount.food.name}}</option>
           {% endfor %}
     </select>
<label>Amount You Need to Pay</label>

<select name="name" class="form-control" required>
        {% for amount in amounts %}
           <option value="{{amount.food.price}}">{{amount.food.price}}</option>
        {% endfor %}
</select>

Answer 1

首先:在模型文件中，更改

model.Models to models.Model

就像你的另一个一样。在进行更改之前，您将无法使用它。

第二:当您尝试在模板中访问此查询集时，您必须按如下方式访问它:

{% for amount in amounts %}
{{ amount.price }}
{{ amount.name }}
{% endfor %}

第三:“相关下拉菜单”

<label>Select the Food</label>
<select name="name" class="form-control" required>
    {% for amount in amounts %}
       <option value="{{amount.food.name}}">Food: {{ amount.name }}, Price: {{ amount.price }}</option>
    {% endfor %}
</select>

当您将查询集传递给模板时，您可以在同一个 for 循环中访问两个表单字段。似乎最好的选择是将这两个选项放在下拉菜单中，因为这意味着它们是相关的。

希望有帮助! :)