无法分配“''”:“ IncomeExpense.username”必须是“ User”实例

问题描述

我正在处理以下代码,尝试通过从表单获取值将数据添加到表中。我还用v_id标记了哪里出错了。

我在下面粘贴了#views.pymodels.py。可能是我收到此错误的原因,并且还向我解释了可以更改以消除此错误的原因。

createentry.html
#views.py

def create_entry_form(request):
    if request.method=='POST':
        entry_type=request.POST.get("expensetype")
        amount=request.POST.get("amount")
        details=request.POST.get("entrydetails")
        capture_date=time.strftime('%Y-%m-%d')
        entry_username=request.POST.get("entryusername")

        entry=IncomeExpense.objects.create(entry_type=entry_type,amount=amount,details=details,capture_date=capture_date,username=entry_username) #getting_error_in_this_line
        entry.save()
        user_balance = UserBalance.objects.filter(username=username).values_list('balance',flat=True)[0]
        if entry_type=="income":
            total_balance = user_balance + amount
        else:
            total_balance=user_balance - amount


        update_balance=UserBalance.objects.get(username=username)
        update_balance.value=total_balance
        update_balance.save()
        return render(request,"homepage.html",{'name':username,'balance':total_balance})

    else:
        return redirect("www.google.com")
<!---- createentry.html ---->
<form action="{% url 'create_entry_form' %}" method="post">
    {% csrf_token %}
<div class="container register-form">
            <div class="form">
                <div class="note">
                    <p>Create Entry Form</p>
                </div>

                <div class="form-content">
                    <div class="row">
                        <div class="col-md-6">
                            <div class="form-group">
                                <select name="expensetype" id="expensetype" class="form-control">
                                    <option value="expensetype">Select Expense Type</option>
                                    <option value="income">income</option>
                                    <option value="expense">expense</option>

                                </select>
                            </div>
                            <div class="form-group">
                                <input type="text" name="amount" id="amount" class="form-control" placeholder="Enter the Amount" value=""/>
                            </div>
                        </div>
                        <div class="col-md-6">
                            <div class="form-group">
                                <input type="text" name="entrydetails" id="entrydetails" class="form-control" placeholder="Enter the entry details" value=""/>
                            </div>
                            <div class="form-group">
                                <input type="text" name="entryusername" id="entryusername" class="form-control" placeholder="{{name}}" value=""/>

                            </div>
                        </div>
                    </div>
                    <button type="submit" class="btnSubmit">Submit</button>
                </div>
            </div>
        </div>
</form>

此外,为什么我会收到错误消息#models.py from django.db import models from django.contrib.auth.models import User class IncomeExpense(models.Model): entry_type=models.CharField(max_length=100) amount=models.IntegerField() details=models.TextField() capture_date=models.DateField() username=models.ForeignKey(User,on_delete=models.CASCADE) def __str__(self): return f"{self.id}" class UserBalance(models.Model): balance=models.IntegerField() username=models.ForeignKey(User,on_delete=models.CASCADE) ,如果更改某些内容,我还会得到另一个类似的错误消息。

我尝试在此方法内将用户名更改为Cannot assign "''": "IncomeExpense.username" must be a "User" instance.

username__username

解决方法

我们在这里使用username字段来保存user id,但是您通过了username

def create_entry_form(request):
    if request.method=='POST':
        entry_type=request.POST.get("expensetype")
        amount=request.POST.get("amount")
        details=request.POST.get("entrydetails")
        capture_date=time.strftime('%Y-%m-%d')
        entry_username=request.POST.get("entryusername")

        entry=IncomeExpense.objects.create(entry_type=entry_type,amount=amount,details=details,capture_date=capture_date,username=request.user) #getting_error_in_this_line
        entry.save()
        user_balance = UserBalance.objects.filter(username=request.user).values_list('balance',flat=True)[0]
        if entry_type=="income":
            total_balance = user_balance + amount
        else:
            total_balance=user_balance - amount


        update_balance=UserBalance.objects.get(username=request.user)
        update_balance.balance=total_balance
        update_balance.save()
        return render(request,"homepage.html",{'name':request.user,'balance':total_balance})

    else:
        return redirect("www.google.com")