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Diana Carolina Hernandez
Asked: 2020-02-23 09:25:55 +0800 CST 2020-02-23 09:25:55 +0800 CST

How do I print the result of the sum aggregation function?

  • 772

I have this in my header:

from django.db.models import Sum

And this is my function:

def matriz_cxp(request, idProveedor=None):
    total = 0

    if idProveedor:
        form = Filtro_Proveedor_Form({'proveedor': idProveedor})
        lista_cxp = CuentaPagar.objects.filter(proveedor=idProveedor)
    else:
        form = Filtro_Proveedor_Form()
        lista_cxp = CuentaPagar.objects.all()

    total = lista_cxp.aggregate(Sum('subtotal'))
    print(total) # provisional

    if request.method == 'POST':
        form = Filtro_Proveedor_Form(request.POST)
        if form.is_valid():
            idProveedor = request.POST.get("proveedor")
            return redirect("matriz_cxp", idProveedor)

    return render(request, 'matriz_cxp__salud.html', {
        'lista_cxp': lista_cxp,
        'total': total,
        'form': form,
    })

But that printprints this:

{'subtotal__sum': 16000}

And I need this:

16000

How do I modify the function call?

python

1 Answers

  1. Best Answer

    The function aggregatesimply adds the field to you as a dictionary key. You can try doing printit like this:

    print(total['subtotal__sum'])

    This happens because you are not passing the parameter to the function and it is taking the name of the field but it is possible to pass it a specific name:

    total = lista_cxp.aggregate(subtotal=Sum('subtotal'))
print(total['subtotal'])
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