Django 运行余额/累计余额

Question

我有一个带有计算余额（运行余额/累积余额）的函数的交易模型，但余额输出作为查询集返回。<QuerySet [{'id': 1, 'cumsum': -9.0}, {'id': 2, 'cumsum': -16.0},{'id': 3, 'cumsum': -21.0}]>如何修复我的函数，以便余额仅显示 10 月 16 日为 -9.00、10 月 18 日为 -16.00、然后 10 月 20 日为 -21.00 的数字。先感谢您。model.pyclass Transaction(models.Model):    transaction_date = models.DateField()    account_nickname = models.ForeignKey(Accounts, on_delete=models.CASCADE)    amount = models.FloatField()    @property    def balance(self):        return Transaction.objects.annotate(cumsum=Func(Sum('amount'),template='%(expressions)s OVER (ORDER BY %(order_by)s)',order_by="id")).values('id', 'cumsum').order_by('id', 'cumsum')views.pydef index(request):    all_transactions = Transaction.objects.all()    context = {        "transactions": all_transactions    }    return render(request,'pages/index.html', context)索引.html        {% for each_transaction in transactions %}        <tr>            <td>{{each_transaction.transaction_date}}</td>            <td>{{each_transaction.account_nickname}}</td>            <td>{{each_transaction.amount}}</td>            <td>{{each_transaction.balance}}</td>        </tr>        {% endfor %}输出：

Answer 1

首先删除你的@property balance功能

然后在views.py

def index(request):

    all_transactions = Transaction.objects.annotate(cumsum=Func(Sum('amount'),template='%(expressions)s OVER (ORDER BY %(order_by)s)',order_by="id"))

    context = {

        "transactions": all_transactions

    }

    return render(request,'pages/index.html', context)

然后在你的index.html

{% for each_transaction in transactions %}

<tr>

    <td>{{each_transaction.transaction_date}}</td>

    <td>{{each_transaction.account_nickname}}</td>

    <td>{{each_transaction.amount}}</td>

    <td>{{each_transaction.cumsum}}</td>

</tr>

{% endfor %}