Django通過自定義方法排序

Question

我的自定義方法實際上是一種計算，我試圖通過管理器避免排序，如果可能的話只使用order_by。有沒有一種方法或一行語法來實現這一點？這裏是我的模型：

class Bet(models.Model): 


    provider = models.ForeignKey(Provider) 
    member = models.ForeignKey(Member) 
    game = models.ForeignKey(Game) 
    status = models.ForeignKey(Status) 
    bet_id = models.CharField(max_length=200) 
    bet_time = models.DateTimeField() 
    bet_amount = models.FloatField() 
    valid_bet_amount = models.FloatField() 
    settlement_amount = models.FloatField() 

    def get_profit(self): 
     return self.settlement_amount - self.valid_bet_amount 

Answer 1

您正在尋找註釋

profit = F('settlement_ammount') - F('valid_bet_amount') 
my_query.annotate(profit=profit).order_by('profit') 

見Using F() with annotations