使用 django-filter 和分页（Django）对总列求和

可以从 django 添加总列，例如，它会为我带来所有销售额的总和，但在添加值时会忽略分页。

这是我的模型：

class Venta(models.Model):
    cliente = models.CharField(max_length=300, verbose_name='Cliente')
    fecha =  models.DateField(auto_now_add=True)
    descripcion = models.CharField(max_length=300, blank=True, verbose_name='Detalle del pedido')
    total = models.DecimalField(decimal_places=2, max_digits=7, verbose_name='Total de la venta')

    def __str__(self):
        return '{}'.format(self.id)

我用django-filter库制作的过滤器

class VentasFilter(django_filters.FilterSet):
    min_date = django_filters.DateFilter(name="fecha", lookup_expr='gte')
    max_date = django_filters.DateFilter(name="fecha", lookup_expr='lte')
    min_total = django_filters.NumberFilter(name="total", lookup_expr='gte')
    max_total = django_filters.NumberFilter(name="total", lookup_expr='lte')
    class Meta:
        model = Venta
        fields = ['cliente','min_date', 'max_date','min_total','max_total']

这里是销售清单的视图：

def filterVenta(request):
    venta_list = Venta.objects.all().order_by('-id')
    venta_filter = VentasFilter(request.GET, queryset=venta_list)
    venta_list = venta_filter.qs
    paginator = Paginator(venta_list,10)
    page = request.GET.get('page')
    try:
        ventas = paginator.page(page)
    except PageNotAnInteger:
        ventas = paginator.page(1)
    except EmptyPage:
        ventas = paginator.page(paginator.num_pages)
    return render(request, 'venta/venta_filter.html', {'filter': venta_filter,'ventas': ventas})

我没有问题，但我想添加所有总数，但它不识别分页，也就是说，如果有 100 个销售额，它应该给我带来100 个销售额的总数，而不仅仅是 10 个总数当有一个过滤器给我带来过滤器的所有销售总额时，它们在分页中也是如此。

以前，当我没有分页时，我使用 jquery 从客户端执行此操作，但现在我有分页，我需要从后端（django）进行总和。

这是我的模板，我在其中进行了求和，但使用 jquery 以防它对某人有所帮助：

{% extends 'base/base.html' %}
{% load widget_tweaks %}
{% block titulo %}Filtros de ventas{% endblock %}
{% block contenido %}
  <nav aria-label="breadcrumb">
    <ol class="breadcrumb">
      <li class="breadcrumb-item"><a href="{% url 'venta:venta_crear' %}">Registrar venta</a></li>
      <li class="breadcrumb-item active" aria-current="page">Ventas</li>
    </ol>
  </nav>
   <form method="get">
    <div class="spaceFilter">
    <div class="card border-info">
      <div class="card-body">
        <h5 class="font-weight-bold">Filtros de ventas:</h5>
        <div class="row">
          <div class="form-group col-sm-4 col-md-3">
            <label for="cliente"><i class="fa fa-user"></i> Cliente: </label>
            {% render_field filter.form.cliente class="form-control" %}
          </div>
        </div>
        <div class="row">
          <div class="form-group col-xs-6 col-sm-3 col-md-3">
            <label for="desdeDate"><i class="fa fa-calendar"></i> Desde: </label>
            {% render_field filter.form.min_date class="form-control" %}
          </div>
          <div class="form-group  col-xs-6 col-sm-3 col-md-3">
            <label for="hastaDate"><i class="fa fa-calendar"></i> Hasta: </label>
            {% render_field filter.form.max_date class="form-control" %}
          </div>
          <div class="form-group col-xs-6 col-sm-3 col-md-3">
            <label for="desdeMonto"><i class="fa fa-dollar"></i> Monto desde: </label>
            {% render_field filter.form.min_total class="form-control" %}
          </div>
          <div class="form-group col-xs-6 col-sm-3 col-md-3">
            <label for="hastaMonto"><i class="fa fa-dollar"></i> Monto hasta: </label>
            {% render_field filter.form.max_total class="form-control" %}
          </div>
        </div>
      <div class="col-md-4 offset-md-4">
      <button type="submit" class="btn btn-primary btn-block btn-md">
        <span><i class="fa fa-filter"></i></span> Filtrar
      </button>
      </div>
      </div>
    </div>
    </div>
  </form>
  <div class="table-responsive-md">
    <table class="table table-striped" id="tabla-today">
      <thead class="thead-dark">
        <tr>
          <th scope="col">#</th>
          <th scope="col">Fecha de venta</th>
          <th scope="col">Cliente</th>
          <th scope="col">Descripción del pedido</th>
          <th scope="col">Total de la venta</th>
          <th scope="col">Acciones</th>
        </tr>
      </thead>
      <tbody>
        {% for venta in ventas %}
      <tr>
        <td>{{ venta.id }}</td>
        <td>{{ venta.fecha}}</td>
        <td>{{ venta.cliente }}</td>
        <td>{{ venta.descripcion }}</td>
        <td><span class="total-list">{{ venta.total }}</span></td>
        <td><a href="{% url 'venta:venta_editar' venta.id %}"><i class="fa fa-eye fa-lg spaceIcon" style="color:#007bff"></i></a>
      <a href="{% url 'venta:venta_eliminar' venta.id %}"><i class="fa fa-trash fa-lg colorDnicos"></i></a>
    </td></td>
      </tr>
    {% empty %}
      <tr>
        <td colspan="8" class="text-center colorVacio">No existen ventas</td>
      </tr>
    {% endfor %}
      </tbody>
      </table>
  </div>
  <span class="current">
        Pagina <span class="colorDnicos">{{ ventas.number }}</span> de
        <span class="colorDnicos">{{ ventas.paginator.num_pages }}</span>.
    </span>
    <ul class="pagination justify-content-center">
        {% if ventas.has_previous %}
            <li class="page-item"><a class="page-link" href="?page=1">&laquo; Inicio</a></li>
        <li class="page-item"><a class="page-link" href="?page={{ ventas.previous_page_number }}">Previous</a></li>
        {% endif %}
        {% for i in ventas.paginator.page_range %}
          {% if ventas.number == i %}
            <li class="page-item active"><span class="page-link">{{ i }} <span class="sr-only">(current)</span></span></li>
          {% else %}
            <li class="page-item"><a class="page-link" href="?page={{ i }}">{{ i }}</a></li>
          {% endif %}
        {% endfor %}
        {% if ventas.has_next %}
        <li class="page-item"><a class="page-link" href="?page={{ ventas.next_page_number }}">Next</a></li>
        <li class="page-item"><a class="page-link" href="?page={{ ventas.paginator.num_pages }}">Ultimo &raquo;</a></li>
        {% endif %}
    </ul>
  <div class="row justify-content-center spaceIndicador">
      <div class="card border-info mb-3" style="max-width: 18rem;">
        <div class="card-header">Total de ventas</div>
        <div class="card-body text-info">
          <p class="card-text">EL monto es de: S/.<span class="totalVentas font-weight-bold"></span></p>
        </div>
      </div>
    </div>
{% endblock %}
{% block javascript %}
    <script type="text/javascript">
      $(document).ready(function(){
        $('#id_min_date').datetimepicker({
            format: 'DD/MM/YYYY',
            locale: 'pe'
        });
        $('#id_max_date').datetimepicker({
            format: 'DD/MM/YYYY',
            locale: 'pe'
        });
        //Calculo de totales
          var sum = 0;
          $(".total-list").each(function(){
          sum += parseFloat($(this).text().replace(',', '.'));
        });
        $('.totalVentas').text(sum.toFixed(2));
      });
    </script>
{% endblock %}