Django的通過

Question

增加了額外的列組，我有以下查詢集：

Pago.objects.filter(created__range=(self.inicio, self.fin)).values('tipo__nombre').annotate(monto=Sum('monto')) 

而且它產生的SQL語句：

SELECT "invoice_tipopago"."nombre", SUM("invoice_pago"."monto") AS "monto" FROM "invoice_pago" INNER JOIN "invoice_tipopago" ON ("invoice_pago"."tipo_id" = "invoice_tipopago"."id") WHERE "invoice_pago"."created" BETWEEN 2015-01-01 00:00:00-06:00 AND 2015-06-04 14:18:00-06:00 GROUP BY "invoice_tipopago"."nombre", "invoice_pago"."modified", "invoice_pago"."created" ORDER BY "invoice_pago"."modified" DESC, "invoice_pago"."created" DESC 

它補充說，我是多餘的修改和創建的列沒有指定，我想知道如何避免它。應該注意的是，Pago是從django-extensions TimeStampedModel類派生而來的。

在此先感謝。

Answer 1

我看了看TimeStampedModel並在類meta設置默認ordering：

class TimeStampedModel(models.Model): 
""" TimeStampedModel 
An abstract base class model that provides self-managed "created" and 
"modified" fields. 
""" 
created = CreationDateTimeField(_('created')) 
modified = ModificationDateTimeField(_('modified')) 

class Meta: 
    get_latest_by = 'modified' 
    ordering = ('-modified', '-created',) 
      # ^^^^^^^^^^^^^^^^^^^^^^^^^^ 
    abstract = True 

see in github

你可能會覆蓋提供了另一種過濾器，以通過排序（如tipo__nombre或monto）例如：

Pago.objects.filter(
    created__range=(self.inicio, self.fin) 
).values(
    'tipo__nombre' 
).annotate(
    monto=Sum('monto') 
).order_by(
    'tipo__nombre' 
)