相关型号的默认值

Question

我有一个邮政编码表和一个人员表。输入人员 zip 时，我需要用相关 zip 表中的城市填充人员城市字段。

编辑：我开始相信这是 Django 无法完成的事情。但可以使用 javascript 来完成。我对此的了解甚至比姜戈还要少。有人吗？

models.py：

from django.db import models

class Zip(models.Model):
    zipcode = models.IntegerField()
    city = models.CharField(max_length=200)

    def __str__(self):
        return str(self.zipcode)

class Person(models.Model):
    name = models.CharField(max_length=200)
    zipcode =  models.ForeignKey('Zip',on_delete=models.CASCADE,related_name="zip_of_this_person")  
    personcity = models.CharField(max_length=200)
    def __str__(self):
        return self.name

表格.py

from django import forms 
from .models import Zip, Person


class ZipForm(forms.ModelForm):
    class Meta:
        model = Zip
        fields = ('zipcode', 'city',)
        


class PersonForm(forms.ModelForm):
    class Meta:
        model = Person
        fields = ('name', 'zipcode', 'personcity' )

views.py

from django.shortcuts import render, redirect, get_object_or_404
from .forms import PersonForm, ZipForm
from .models import Zip, Person



# Create your views here.
def index(request):
    return render(request, 'theapp/index.html' )

def person_new(request):
    if request.method == "POST":
        form = PersonForm(request.POST)
        # author_name = '2222'.Zip.city

        if form.is_valid():
            post = form.save(commit=False)
            post.save()
            return redirect('person_detail', pk=post.pk)
        
    else:
        form = PersonForm()
    return render(request, 'theapp/person.html', {'form': form})

def zip_new(request):
    if request.method == "POST":
        form = ZipForm(request.POST)

        if form.is_valid():
            post = form.save(commit=False)
            post.save()
            return redirect('zip_detail', pk=post.pk)
    else:
        form = ZipForm()
    return render(request, 'theapp/zip.html', {'form': form})

def person_detail(request, pk):
    post = get_object_or_404(Person, pk=pk)
    weather= "testing purposes"
    context= {
        'post': post,
        'weather': weather,
        }
    return render(request, 'theapp/person_detail.html', context)

def zip_detail(request, pk):
    post = get_object_or_404(Zip, pk=pk)
    return render(request, 'theapp/zip_detail.html', {'post': post})

最后是 html：

{% extends 'theapp/base/base.html' %}
{% load static %}

{% block title %}Tittel Tab{% endblock %}

{% block site_css %}{% endblock %}
{% block main_heading %}{% endblock %}   

{% block header_content %}{% endblock %}


{% block body %}
<section>
    <h2>Person</h2>
</section>

<article class="post">
    <h2>Name:{{ post.name }}</h2>
    <p>Zip/city:{{ post.zipcode }}{{ post.personcity }}</p>
    {{weather}}

        
</article>


{% endblock %}

所以我一直在寻找，但没有真正找到任何对我有帮助的东西。我无法找到任何解决方案。如果是相反的方式显示所有相关的 ti zip，那就很容易了。我意识到这可能是一个前端问题，也许不完全是 Django 的问题。但使用关系数据库仍然是非常基本的。任何帮助都表示感谢。

Answer 1

您可以在personcity上允许空和空白，然后在保存模型时填充它； 为此，您可以采用简单的方法并重写 .save() 方法 像这样的事情：

class Person(models.Model):
    name = models.CharField(max_length=200)
    zipcode =  models.ForeignKey('Zip',on_delete=models.CASCADE,related_name="zip_of_this_person")  
    personcity = models.CharField(max_length=200, null=True, blank=True)
    def __str__(self):
        return self.name

    def save(self, *args, **kwargs):
        if not self.personcity and self.zipcode and self.zipcode.city:
            self.personcity  = self.zipcode.personcity
        super(Message, self).save(*args, **kwargs)

或者你可以使用 pre_save 信号

来做到这一点