擅长:python、mysql、java
<p><code>ForeignKey</code>由<code>django.forms.ModelChoiceField</code>表示,这是一个ChoiceField,它的选择是一个模型查询集。摘自<a href="https://docs.djangoproject.com/en/1.10/topics/forms/modelforms/#field-types" rel="nofollow noreferrer">documentation</a></p>
<p>你的<code>Expense Model</code>可能是这样的:</p>
<pre><code>class Expense(models.Model):
category = models.ForeignKey(Category)
add_date = models.DateField()
amount = models.DecimalField(max_digits=10, decimal_places=2)
</code></pre>