NULL约束失败: forum_thread.title

Question

我最近学习了Django并想做一些项目，我想让它成为一个论坛网站，但是当我在做一个讨论论坛时，当我登录并发布数据时，我会得到以下错误：

NULL约束失败: forum_thread.title

models.py

from django.db import models
from django.utils.timezone import now
from django.contrib.auth.models import User
from datetime import datetime 

class Thread(models.Model):
    sno = models.AutoField(primary_key=True)
    title = models.CharField(max_length=255)
    slug = models.SlugField(max_length=255)
    category = models.ForeignKey('category', related_name="Thread", on_delete=models.CASCADE)
    user = models.ForeignKey(User, on_delete=models.CASCADE)
    description = models.TextField()
    timestamp = models.DateTimeField(default=datetime.now, blank=True)

    def __str__(self):
        return self.title

class Category(models.Model):
    sno = models.AutoField(primary_key=True)
    name = models.CharField(max_length=100)
    slug = models.SlugField(max_length=100)
    description = models.TextField()
    timestamp = models.DateTimeField(default=datetime.now, blank=True)

    class Meta:
        verbose_name_plural = "Categories"

views.py

from django.shortcuts import render, redirect
from django.http import HttpResponse
from django.contrib.auth.models import User
from django.contrib.auth import authenticate, login, logout
from django.contrib import messages
from .models import Thread, Category

def addThread(request):
    if request.method == "POST":
        thread_title = request.POST.get('threadtitle')
        thread_slug = request.POST.get('threadslug')    
        thread_category = request.POST.get('threadcategory')    
        thread_description = request.POST.get('threaddescription') 
        user = request.user  
        thread = Thread(title = thread_title, slug = thread_slug, category=thread_category, 
        description = thread_description, user = user) 
        thread.save() 
        messages.success(request, 'thread added successfully')
    return redirect('home')   

Answer 1

您可以简单地更改函数，如def str(self)：返回self.title

def __str__(self):
    if self.name:
        return self.title
    return 'Untitled

Answer 2

根据Thread模型，数据库中的标题不能为空。因此，确保HTML是必需的，并且request.POST.get('threadtitle')是存在的，并且有一个值。