如何根據 function 輸入進行 django 查詢？

Question

我想根據 function 輸入進行 django 查詢。我不想在 2 個單獨的行中使用 if 和 else 檢查輸入，然后進行如下查詢：

def customer_number(mall,store=None):
    if store :
        customer = models.Customer.objects.filter(mall=mall,store=store)
    else :
        customer = models.Customer.objects.filter(mall=mall)
    return customer.count

Answer 1

您可以構造一個查找 kwarg 字典：

def customer_number(mall, store=None):
    lookup_kwargs = {'mail': mail}
    if store:
        lookup_kwargs['store'] = store
    return models.Customer.objects.filter(**lookup_kwargs).count()

或者，如果您不想要任何條件，您可以構造dict並刪除None值：

def customer_number(mall, store=None):
    lookup_kwargs = {'mail': mail, 'store': store}
    lookup_kwargs = {k: v for k, v in lookup_kwargs.items() if v is not None}
    return models.Customer.objects.filter(**lookup_kwargs).count()