Question

from django.contrib.auth.models import Permission, User
from django.db import models
from django.utils import timezone


class Movement(models.Model):
    startDate = models.DateField(default=timezone.now)
    recordTime = models.DateTimeField(default=timezone.now)
    endDate = models.DateField(max_length=50)
    purpose = models.CharField(max_length=250)
    location = models.CharField(max_length=250)
    noOfDays = models.IntegerField
    vehicleType = models.CharField(max_length=100)
    bookingStatus = models.CharField(max_length=250)
    done = models.BooleanField(default=False)
    cancelled = models.BooleanField(default=False)

    def __dir__(self):
        return self.location + '|' + self.done + '|' + self.cancelled


class Report(models.Model):
    createdOn = models.DateField(default=timezone.now)
    SubmittedOn = models.DateField(default=timezone.now, 
    null=True,blank=True)
    userName = models.CharField(max_length=250)
    weekNo = models.CharField(max_length=20)
    location = models.CharField(max_length=100)
    projectCode = models.CharField(max_length=100)
    totalAmount = models.FloatField(max_length=300, default=0)
    flatsComment = models.CharField(max_length=300, default="")
    financeComment = models.CharField(max_length=300, default="")

    def __str__(self):
        return self.userName + '|' + self.location + '|' + self.weekNo


class Expense(models.Model):
    report = models.ForeignKey(Report, on_delete=models.CASCADE)
    date = models.DateField(default=timezone.now)
    item = models.CharField(max_length=250)
    unit = models.CharField(max_length=20)
    unitPrice = models.FloatField(max_length=100)
    quantity = models.FloatField(max_length=100)
    total = models.FloatField(max_length=250)
#views.py

from django.shortcuts import render, redirect, get_object_or_404
from django.contrib import messages
from django.db.models import Avg, Count, Min, Sum
from django.http import Http404, HttpResponse, HttpResponseRedirect
from django.views import generic
from .models import *
from .forms import *


# Create your views here.
def programme(request):
return render(request, 'prog/prog.html', {})


def create_report(request):
    form = ReportForm(request.POST or None, request.FILES or None)
    object_list = Report.objects.all()
    if form.is_valid():
        report = form.save(commit=False)
        report.save()
        expense.save()
        report.totalAmount =          Expense.objects.aggregate(Sum('espence_total'))
    return redirect('prog:reports')
else:
    context = {
        'form': form,
        'object_list': object_list
        }
return render(request,'prog/form_create_financial_report.html', context)


class ReportView(generic.ListView):
    totalAmount = Expense.objects.aggregate(sum(expense_total))['totalAmount']
    template_name = 'prog/report_status.html'

    def get_queryset(self):
        return Report.objects.all()


def report_edit(request, report_id):
    report = Report.objects.get(id=report_id)
    form = ReportForm(request.POST or None, instance=report)
    object_list = Report.objects.all()
    if form.is_valid():
        report.save()
        messages.success(request, ('the report has been updated'))
        return redirect('prog:reports')
    else:
        context = {
            'form': form,
            'object_list': object_list
        }
    return render(request, 'prog/form_edit_report.html', context)


def delete_report(request, report_id):
    report = get_object_or_404(Report,id=report_id)
    form = ReportForm(request.POST or None, instance=report)
    object_list = Report.objects.all()
    if form.is_valid():
        report.delete()
        return redirect('prog:reports')
    else:
        context = {
            'form': form,
            'object_list': object_list
        }
    return render(request, 'prog/form_delete_report.html', context)


def report_detail(request, report_id):
    report = get_object_or_404(Report,id=report_id)

    return render(request, 'prog/report_detail.html',{'report':report})


def create_expense(request, report_id):
    form = ExpenseForm(request.POST or None, request.FILES or None)
    report = get_object_or_404(Report,pk=report_id)
    if form.is_valid():
        expense = form.save(commit=False)
        expense.report =report
       return render(request, 'prog/report_detail.html', {'report':report})
    context ={
        'report':report,
        'form':form
    }
    return render(request, 'prog/form_create_expense.html', context)

我希望结果是属于报表对象的所有costum_total的总和。每当创建新费用时，其总费用应自动添加到report_toalAmount。创建费用后，应该自动填充report.totalAmount

并传递到report_detail（Listview）中的模板

Answer 1

您可以使用Django信号装饰器来“监听”数据库中的更改。

某些事情应该起作用：

@receiver(post_save, sender=Expense)
def update_report(sender, instance, created, **kwargs):
    if created: #validate a new object was created and not updated
         report = Report.objects.get() #use the primary key of your report
         report.totalAmount += instance.total
         report.save()

我们在信号装饰器中使用post_save，这样该函数将仅在创建模型后执行。

instance参数是已经创建的模型，我们可以使用它来检索所需的数据。我建议您阅读有关信号的信息，它们经常派上用场。

创建费用后，报表对象将立即更新。只需将其作为参数传递到report_detail视图，就应该一切就绪。

正如有人已经在评论部分中建议的那样，请查看Django Signals，以进一步阅读该主题。

我想汇总费用总计并返回该值作为Report total in totalAmount

1 个答案: