Django 模型 : Multiplication of two fields

Question

我想将模型中的两个字段相乘并将其显示在模板中。我有两个模型:

class Priority(models.Model):
    priorityName=models.CharField(max_length=100)
    priorityScore=models.IntegerField()
    def __str__(self):
        return str(self.priorityScore)

class ImpactMatrix(models.Model):
    objectName=models.ForeignKey(ObjectName,on_delete=models.CASCADE)
    actionName=models.ForeignKey(ActionObject,on_delete=models.CASCADE)
    priority=models.ForeignKey(Priority,on_delete=models.CASCADE,related_name='priority')
    functional=models.ForeignKey(Priority,on_delete=models.CASCADE,related_name='functional')
    supervision=models.ForeignKey(Priority,on_delete=models.CASCADE,related_name='supervision')
    approval=models.ForeignKey(Priority,on_delete=models.CASCADE,related_name='approval')

我想乘以 ImpactMatrix.priority * ImpactMatrix.functional 中的 priorityScore

我该怎么做呢？

Answer 1

定义一个 @property 在模型中并像任何其他模型字段一样从模板访问它，

class ImpactMatrix(models.Model):
    objectName = models.ForeignKey(ObjectName, on_delete=models.CASCADE)
    actionName = models.ForeignKey(ActionObject, on_delete=models.CASCADE)
    priority = models.ForeignKey(Priority, on_delete=models.CASCADE, related_name='priority')
    functional = models.ForeignKey(Priority, on_delete=models.CASCADE, related_name='functional')
    supervision = models.ForeignKey(Priority, on_delete=models.CASCADE, related_name='supervision')
    approval = models.ForeignKey(Priority, on_delete=models.CASCADE, related_name='approval')

    @property
 def some_name(self):
 return self.priority.priorityScore*self.functional.priorityScore

在你的情调中，

{% impactmatrix_object.some_name %}