Question

我有一个页面可以编辑模型中的现有数据。

模型：

class billitem(models.Model):
    code = models.AutoField(primary_key=True, unique=True)
    name = models.CharField(max_length=35)
    description = models.CharField(max_length=60, null=True)
    price = models.DecimalField(decimal_places=2, max_digits=8)

表格：

class BillItem(forms.Form):
    code = forms.IntegerField(max_value=100000, disabled=True)
    name = forms.CharField(label='Item Name', max_length=32)
    description = forms.CharField(
        label='Description', max_length=57, required=False)
    price = forms.DecimalField(decimal_places=2, max_digits=8)

视图是：

def edit_bill_item(request, itemcode):
    if request.method == 'POST':
        form = BillItem(request.POST)
        code = request.POST.get('code')
        name = request.POST.get('name').title()
        description = request.POST.get('description')
        price = request.POST.get('price')
        billitem.objects.filter(code=code).update(
            name=name, description=description, price=price)
        msg = 'Successfully saved Billing item.'
        # form = BillItem(request.POST)
        return render(request, 'billing/edititem.html', {'form': form, 'msg': msg})
    else:
        itemcode = int(itemcode)
        item = get_object_or_404(billitem, code=itemcode)
        form = BillItem(initial={
            'code': item.code,
            'name': item.name,
            'description': item.description,
            'price': item.price
        })
        return render(request, 'billing/edititem.html', {'form': form})

问题在于，每次提交POST时，表中都会使用新代码添加另一个条目，而不是更新现有行。

我也尝试过：

item = billitem(code=code, name=name, description=description, price=price)
item.save()

备用：

class BillItem(ModelForm):
    class Meta:
        model = billitem
        fields = ['code', 'name', 'description', 'price']


def edit_bill_item(request, itemcode):
    if request.method == 'POST':
        code = request.POST.get('code')
        name = request.POST.get('name').title()
        description = request.POST.get('description')
        price = request.POST.get('price')
        item = billitem.objects.get(code=code)
        form = BillItem(request.POST, instance=item)
        form.save()
        msg = 'Successfully saved Billing item.'
        return render(request, 'billing/edititem.html', {'form': form, 'msg': msg})
    else:
        itemcode = int(itemcode)
        item = get_object_or_404(billitem, code=itemcode)
        form = BillItem(initial={
            'code': item.code,
            'name': item.name,
            'description': item.description,
            'price': item.price
        })
        return render(request, 'billing/edititem.html', {'form': form})

也有同样的效果。如何仅在模型和表单中处理现有数据的更新。

Answer 1

更改此行：

billitem.objects.filter(code=code).update(name=name, description=description, price=price)

要使用内置的update_or_create函数（https://docs.djangoproject.com/en/dev/ref/models/querysets/#update-or-create）

BillItem.objects.update_or_create(code=code, defaults={'name':'name', 'description':'description', 'price':'price})

更新数据，而不是在Django模型中创建新的行条目

1 个答案: