利用注释进行列表标注

Question

目前，我有一个观点，显示我所有的投资到期在未来5年内，为每个客户。我想做的是显示每个金融机构的总额，如下所示：

机构|金额|到期金额

TD | 1000 | 1250
苏格兰| 1203 | 9383

等等

这是我用来显示未来5年到期投资价值的代码。你知道吗

#get the invesments maturing this year
        for p in plans:
            cur_inv = Investment.objects.all().filter(plan = p).order_by('financial_institution').filter(maturity_date__year = current_year)
            nxt_inv = Investment.objects.all().filter(plan = p).order_by('financial_institution').filter(maturity_date__year = next_yr)
            thr_inv = Investment.objects.all().filter(plan = p).order_by('financial_institution').filter(maturity_date__year = thr_yr)
            fr_inv = Investment.objects.all().filter(plan = p).order_by('financial_institution').filter(maturity_date__year = fr_yr)
            fv_inv = Investment.objects.all().filter(plan = p).order_by('financial_institution').filter(maturity_date__year = fv_yr)

            for inv in cur_inv:
                total += inv.amount or 0
            for inv in cur_inv:
                total_m += inv.maturity_amount or 0

            for inv in nxt_inv:
                total2 += inv.amount or 0
            for inv in nxt_inv:
                total_m2 += inv.maturity_amount or 0

            for inv in thr_inv:
                total3 += inv.amount or 0
            for inv in thr_inv:
                total_m3 += inv.maturity_amount or 0

            for inv in fr_inv:
                total4 += inv.amount or 0
            for inv in fr_inv:
                total_m4 += inv.maturity_amount or 0

            plan_list.append({
                'plan':p,
                'investment': cur_inv,
                'nxt_inv': nxt_inv,
                'thr_inv': thr_inv,
                'fr_inv': fr_inv,
                'fv_inv': fv_inv,
            })

我使用一个列表来存储我的所有计划，这样我就可以为模板上的每个计划运行for循环。你知道吗

我有一个类似的观点，我希望这一个做什么，但只有一个计划，我不知道如何让它与多个计划的工作。你知道吗

这是我的代码，如果它只是一个选定的计划。你知道吗

#Calculate the holding totals with each company
        total_list = plan.investment_set.filter(maturity_date__gte= '%s-1-1' % current_year).values('financial_institution__abbr').annotate(Sum('maturity_amount')).order_by('financial_institution__abbr')
        context['list'] = total_list

如果有人能帮忙，我将不胜感激。你知道吗

谢谢。你知道吗

Answer 1

看起来您可能可以让您的数据库为您计算这个。你知道吗

在SQL中，这可能类似于：

SELECT sum(investment.amount)
FROM investment, maturity_date
WHERE investment.id = maturity_date.investment_id and year=%s
GROUP BY investment.amount

看看Django's documentation for aggregation，看看有没有适合你的问题。你知道吗

另一方面，Django的queryset api是generative，因此您可以简化查询的构建：

investments = Investment.objects.all().filter(plan = p).order_by('financial_institution')
cur_inv = investments.filter(maturity_date__year = current_year)
nxt_inv = investments.filter(maturity_date__year = next_yr)
thr_inv = investments.filter(maturity_date__year = thr_yr)
fr_inv = investments.filter(maturity_date__year = fr_yr)
fv_inv = investments.filter(maturity_date__year = fv_yr)

编辑：我自己还没有尝试过，但是聚合文档的this part看起来是一个好的开始。你知道吗