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确保模型中至少有一个领域得到具体规定的最佳方式?
原标题:Best way to ensure that at least one field in a model is specified?

我有一个模式,有四个领域,所有这些领域都作了界定。 我想防止形成一个完全无效的模式;我不使用一个有效手段,因为我想与缺省行政合作。

如果我凌驾于“储蓄(储蓄)”方法进行核对,那么我究竟会产生什么错误?

最佳回答

你们能够真正地提出任何东西,这 up你们。 在这种情况下,数值可能比较合适。

问题回答

我将把它列入<代码>save()。 这样,就会产生一种惯例错误,你可以在任何地方尝试/捕获物,除非采用这一模式。

class EmptyModelDetected(Exception):
    pass

# Then in your save method
def save(self, *args, **kwargs):
    if self.field1 or self.field2 or self.field3 or self.field4:
        super(Model, self).save(*args, **kwargs)
    else:
        raise EmptyModelDetected()

# Then, wherever you call save
try:
    m.save()
except EmptyModelDetected:
    # handle the error




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