Django 中的 ModelForm 不知道属性已填充 - NOT NULL 约束失败：teretana_pretplatnik.first_name

Question

我正在按照本教程制作 Django Gym 应用程序 https://www.youtube.com/watch?v=Mag1n3MFDFk&list=PL2aJidc6QnyOe-fp1m4yKHjcInCRTF53N&index=3 我想编写一个用户（登录后）可以填写并成为订阅者的表单页面。在教程中，他使用了一个新模型 Enrollment 来填充数据，但我有一个模型 Pretplatnik（英语为订阅者），它与 django 用户模型具有 OneToOne 关系。 还有另外两个模型，即用户可以订阅的 Plan 的 FK 到 Pretplatnik 和用户可以选择的 Trainer 模型。

模型.py

from django.db import models
from django.contrib.auth.models import User


# Create your models here.

class Oznaka(models.Model):
    naziv = models.CharField(max_length=200)

    def __str__(self):
        return self.naziv

class Plan(models.Model):
    naziv=models.CharField(max_length=150)
    cijena=models.IntegerField()
    max_clanova=models.IntegerField(null=True)
    oznake=models.ManyToManyField(Oznaka, default=None, blank=True, related_name='oznake')

    def __str__(self):
        return '%s' % self.naziv


class Trener(models.Model):
    ime=models.CharField(max_length=150)
    image=models.ImageField(upload_to='static/assets/img/team', default=None)

    def __str__(self):
        return self.ime

class Pretplatnik(models.Model):
    korisnik=models.OneToOneField(User, on_delete=models.CASCADE)
    trener=models.ForeignKey(Trener, on_delete=models.CASCADE, related_name='pretplatnici')
    plan=models.ForeignKey(Plan, on_delete=models.CASCADE, null=True)
    datum_r=models.DateField(blank=True,null=True)
    spol=models.CharField(max_length=25, default=None)
    adresa=models.CharField(max_length=150)

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

class Pretplata(models.Model):
    pretplatnik=models.ForeignKey(Pretplatnik, on_delete=models.CASCADE, null=True)
    plan=models.ForeignKey(Plan, on_delete=models.CASCADE, null=True)

class CustomModelName(models.Model):
    user = models.ForeignKey(User, on_delete=models.CASCADE)

from django import forms
from django.forms import ModelForm
from teretana.models import *

class PretplatnikForm(forms.ModelForm):
    plan = forms.ModelChoiceField(queryset=Plan.objects.all(),
                                    to_field_name = 'naziv',
                                    empty_label="Select Plan")
    
    trener = forms.ModelChoiceField(queryset=Trener.objects.all(),
                                    to_field_name = 'ime',
                                    empty_label="Select Trainer")

    class Meta:
        model = Pretplatnik
        fields = ['trener', 'plan', 'datum_r', 'spol', 'adresa']
        GENDER_CHOICES = (
            ('', 'Select a Gender'),
            ('Female', 'Female'),
            ('Male', 'Male'),
        )
        widgets = {
            'trener':forms.TextInput(attrs={'class':'form-control','placeholder':'Select Trainer'}),
            'plan':forms.TextInput(attrs={'class':'form-control','placeholder':'Select Plan'}),
            'datum_r':forms.DateInput(attrs={'class':'form-control','placeholder':'Enter Date of Birth'}),
            'spol':forms.Select(choices=GENDER_CHOICES,attrs={'class': 'form-control'}),
            'adresa':forms.TextInput(attrs={'class':'form-control','placeholder':'Enter Address'}),
        }
        labels={
            'plan':'Select Plan',
            'trener':'Select Trainer',
            'datum_r':'Datum_r',

        }

views.py

def enroll(request):

    if request.method == 'POST':
        form = PretplatnikForm(request.POST)
        if form.is_valid():
            form.save()


    form = PretplatnikForm()
    return render(request, 'enroll.html', {'form': form})

注册.html

{% extends 'base.html' %} 
{% block title %} Enrollment for Gym {% endblock title%}
{% block head %}

<h2>Join The Best Gym In Rijeka</h2>
    

<div class="container mt-2">
  <div class="row">
    <div class="col-md-3"></div>

    <div class="col-md-6">
      {% for message in messages %}
      <div
        class="alert alert-{{message.tags}} alert-dismissible fade show"
        role="alert"
      >
        <strong></strong> {{message}}
        <button
          type="button"
          class="btn-close"
          data-bs-dismiss="alert"
          aria-label="Close"
        ></button>
      </div>
      {% endfor %}



      <form action="/enroll" method="post">{% csrf_token %}
        {% csrf_token %}
        <div class="form-group">
    
          <label class="form-label">{{form.trener.label_tag}}</label>
          {{form.trener}}
      </div>



      <form action="/enroll" method="post">{% csrf_token %}
        {% csrf_token %}
      <div class="form-group">
    
        <label class="form-label">{{form.plan.label_tag}}</label>
        {{form.plan}}
    </div>



  <form action="/enroll" method="post">{% csrf_token %}
    {% csrf_token %}
  <div class="form-group">

    {{form.spol}}
</div>

<br>

<form action="/enroll" method="post">{% csrf_token %}
  {% csrf_token %}
<div class="form-group">
  {{form.adresa}}
</div>

<br>

<form action="/enroll" method="post">{% csrf_token %}
  {% csrf_token %}
<div class="form-group">
  {{form.datum_r}}
</div>

<br>
        <div class="form-group">
          <input
            type="number"
            class="form-control mt-2"
            value="{{user.username}}"
            name="PhoneNumber"
            placeholder="Enter Your Number"
            readonly
            required
          />
        </div>

            </div>


        <br>
        <div class="d-grid gap-2">
          <button class="btn btn-warning" type="submit">Enroll</button>
        </div>
      </form>
    </div>

    <div class="col-md-3"></div>
  </div>
</div>

{% endblock head %}

他正在使用 HTML 表单来获取数据，但我尝试过，但它对 FK 不起作用（或者它起作用，但我不知道如何实现它），所以我尝试使用 ModelForm。但现在我得到这个错误，因为我假设 ModelForm 不知道 django 用户数据（Pretplatnik 的 PK）已经填充（除非登录，否则用户无法填写表单）。 我尝试更改视图文件，就像我在此处发布的另一个问题中看到的那样，但随后出现错误： /enroll 处出现属性错误

“Pretplatnik”对象没有属性“is_valid”

views.py

def enroll(request):
    if not request.user.is_authenticated:
        messages.warning(request,"Please Login and Try Again")
        return redirect('/login')


    if request.method == 'POST':
        form = PretplatnikForm(request.POST)
        form = form.save(commit=False)
        if form.is_valid():
            form.save()


    form = PretplatnikForm()
    return render(request, 'enroll.html', {'form': form})

Answer 1

这不一定是答案，但这里看起来很奇怪：

    if request.method == 'POST':
        form = PretplatnikForm(request.POST)
        form = form.save(commit=False) # not sure why this is here
        if form.is_valid():
            form.save()

通常人们会看到这种模式，其中 commit=False 遵循验证。我不清楚您想如何使用它，或者如何为 korisnik 字段添加一对一，但这里有一个通常可能使用的示例。

    if request.method == 'POST':
        form = PretplatnikForm(request.POST)
        if form.is_valid():
            new_sub = form.save(commit=False)
            new_sub.korisnik = korisnik_object # queried elsewhere
            new_sub.save() # no need to call form.save()