Question

我尝试通过其URL获取图像并将其保存到数据库但是我在/ images / create /中得到 IntegrityError - NOT NULL约束失败：images_image.user_id 向我抛出。以下是可能涉及的文件

models.py

（包含覆盖save()方法的代码，以根据slug字段的值自动生成title字段

from django.db import models
from django.conf import settings
from django.utils.text import slugify

class Image(models.Model):
    user = models.ForeignKey(settings.AUTH_USER_MODEL, related_name='images_created')
    title = models.CharField(max_length=200)
    slug = models.SlugField(max_length=200, blank=True)
    url = models.URLField()
    image = models.ImageField(upload_to='images/%Y/%m/%d')
    description = models.TextField(blank=True)
    created = models.DateField(auto_now_add=True, db_index=True)
    users_like = models.ManyToManyField(settings.AUTH_USER_MODEL, 
    related_name='images_liked', blank=True)

    def __str__(self):
        return self.title

    def save(self, *args, **kwargs):
        if not self.slug:
            self.slug = slugify(self.title)
            super(Image, self).save(*args, **kwargs)

forms.py

（包含覆盖save()方法以检索给定图像并保存的代码）

from urllib import request
from django import forms
from django.core.files.base import ContentFile
from django.utils.text import slugify
from .models import Image

class ImageCreateForm(forms.ModelForm):
    class Meta:
        model = Image
        fields = ('title', 'url', 'description')
        widgets = {
            'url' : forms.HiddenInput,
        }

    def clean_url(self):
        url = self.cleaned_data['url']
        valid_extensions = ['jpg', 'jpeg']
        extension = url.rsplit('.', 1)[1].lower()
        if extension not in valid_extensions:
            raise forms.ValidationError('the given URL doesn\'t match valid image extensions')
        return url

    def save(self, force_insert=False, force_update=False, commit=True):
        image = super(ImageCreateForm, self).save(commit=False)
        image_url = self.cleaned_data['url']
        image_name = '{}.{}'.format(slugify(image.title),
        image_url.rsplit('.', 1)[1].lower())

        # Download image from given URL
        response = request.urlopen(image_url)
        image.image.save(image_name, ContentFile(response.read()))

        if commit:
            image.save()
        return image

views.py

from django.shortcuts import render, redirect
from django.contrib.auth.decorators import login_required
from django.contrib import messages
from .forms import ImageCreateForm

@login_required
def image_create(request):
    if request.method == 'POST':
        # Form is sent
        form = ImageCreateForm(data=request.POST)
        if form.is_valid():
            # Form data is valid
            cd = form.cleaned_data
            new_item = form.save(commit=False)

            # Assign current user to the item
            new_item.user = request.user
            new_item.save()
            messages.success(request, 'Image added successfully')

            # Redirect to the newly created item detail view
            return redirect(new_item.get_absolute_url())
    else:
        # Build form with data provided by the bookmarklet via GET
        form = ImageCreateForm(data=request.GET)

    return render(request, 'images/image/create.html',
    {'section' : 'images', 'form' : form})

怎么了？请有人帮忙

Answer 1

我觉得你在import java.io.File; import java.io.IOException; import java.util.Scanner; public class fileToMatrix { public static void main(String[] args) throws IOException { File f = new File("./src/floatMat.txt"); Scanner s = null; int m=-1; float value = -0.1f; try { s = new Scanner(f); if(s.hasNextLine()) { // Firstly, read the dimension number m = s.nextInt(); System.out.println("Dimension of the matrix = " + m + "x" + m); } float [][] mat = new float[m][m]; //creates a matrix of dimension m for(int i=0; i< m; i++){ //and initializes to 0 for(int j=0; j< m; j++){ mat[i][j] = 0.0f; } } if(s.hasNextLine()) { for(int r=0; r< m; r++){ for(int c=0; c< m; c++){ value = s.nextFloat(); //PROBABLY HERE'S THE MISTAKE!!!!! mat[r][c] = value; //set value on the current cell of the array } } } for(int i=0; i< m; i++){ //print the matrix for(int j=0; j< m; j++){ System.out.print(mat[i][j]+ " "); } System.out.println(); } } catch (Exception ex) { System.out.println("Message catch: " + ex.getMessage()); } finally { if (s != null) s.close(); } } }方法中遇到麻烦，当你试图保存图片时，django需要保存实例，所以你有错误，我的解决方案是添加用户来形成数据：

表格

save

在视图中

class ImageCreateForm(forms.ModelForm):
    class Meta:
        model = Image
        fields = ('title', 'url', 'description', 'user')
        widgets = {
            'url': forms.HiddenInput,
            'user': forms.HiddenInput,
        }

/ images / create /中的IntegrityError - NOT NULL约束失败：images_image.user_id

1 个答案: