Question

如果在我的模型中，Moneybook有很多积压记录。

所以，我设计了一个模型

Moneybook / models.py

   name = models.CharField(max_length=30, default="행복한 여행!")
    owner = models.ForeignKey(
        user_models.User, on_delete=models.CASCADE, related_name="owner")
    companion = models.ManyToManyField(
        user_models.User, related_name="companion", blank=True)
    country = CountryField()
    location = models.CharField(max_length=50, blank=True)
    start_date = models.DateTimeField(default=NOW)
    end_date = models.DateTimeField(default=NOW)

Moneylog / models.py

moneybook = models.ForeignKey(
    moneybook_models.Moneybook, on_delete=models.CASCADE, related_name="moneybooks")
payer = models.ForeignKey(
    user_models.User, on_delete=models.CASCADE, related_name="payer")
dutch_payer = models.ManyToManyField(
    user_models.User, related_name="dutch_payer")
price = models.IntegerField()
category = models.CharField(max_length=10)
memo = models.TextField()

如果我想在每个所属的资金簿中加载所有资金记录。我如何加载它？

我想...

def moneybook_detail(request, pk):
    moneylogs=moneylog.filter(moneylog.moneybook.id=request.moneybook.id)
    return render(request, "moneybooks/detail.html")

但发生错误。

moneylogs = moneylog.filter(request.moneybook.id=request.moneybook.id)
SyntaxError: keyword can't be an expression

Answer 1

您可以使用双下划线__根据引用的对象字段进行过滤，从而通过以下查询查询Moneylog表。

moneylogs = MoneyLog.filter(moneybook__id=<<<MoneyBookID_GOES_HERE>>>)

或者通过在Django中使用内部ReverseManyToOneManager

只需使用

moneybook = MoneyBook.objects.get(pk=<<<<MoneyBookID_GOES_HERE>>>>)
moneylogs = moneybook.moneylog_set.all() # all() to get all money logs
# You can do filter(...) on it too to filter the moneylogs too.

这将返回与存折有关的所有货币记录。

Answer 2

通常，您必须使用双下划线__来引用过滤器中的外键列：

def moneybook_detail(request, pk):
    moneylogs=moneylog.filter(moneybook__id=request.moneybook.id)
    return render(request, "moneybooks/detail.html")

如何打印外键模型关系？

2 个答案: