python - Django 根据 GET 请求从数据库中查询过滤后的数据

Question

我正在学习django，想根据用户的请求查询数据。这是我的代码:

模型.py:

class Airline(models.Model):
    name = models.CharField(max_length=10, blank=True, null=True)
    code = models.CharField(max_length=2, blank=True, null=True)

class FinancialData(models.Model): 
    airline = models.ForeignKey(Airline)
    mainline_revenue = models.DecimalField(max_digits=7, decimal_places=2)
    regional_revenue = models.DecimalField(max_digits=7, decimal_places=2)
    other_revenue = models.DecimalField(max_digits=7, decimal_places=2)
    total_revenue = models.DecimalField(max_digits=7, decimal_places=2)

网址.py:

urlpatterns = [
    url(r'^airline/(?P<pk>\d+)/$', views.airlinesdata, name='airline_data'),
]

views.py:

def airlinedata(request):
    data = FinancialData.objects.filter(pk=airline_id)
    return data

我不确定我应该在 views.py 中写什么，当用户选择例如 airline_id 3 时，它会检索 FinancialData从该航空公司的数据库中仅使用外键？

Answer 1

如果 Airline 是 FinancialData 的外键，则 Airline 与 FinancialData 之间存在一对多关系。这意味着:

  obj = Airline.objects.get(pk=3)

会给你一个单一的对象。这个对象有很多附加到它的金融数据，你可以通过说:

  financial_data = obj.financial_data_set.all() //Django has _set for all ForeignKey relationship.

一旦您的 View 将 pk 作为参数，您就可以从财务数据查询航空公司，反之亦然:

   def airlinedata(request, pk):
       financial = FinancialData.objects.filter(airline__pk=pk)
       # Notice the double underscore, it's called field lookup. You can lookup fields in other model from a model using it.
       # If u get your airline data first however by using:
       airline = Airline.objects.get(pk=pk)
       # You can obtain all financial data attached to it thus:
       financials = airline.fiancial_data_set.all()

希望对您有所帮助!