如何通过Django外键描述进行查询？

Question

if i have this code

class Father(models.Model):
    Description = models.CharField(max_length=50)
    Code        = models.IntegerField(max_length=2, unique=True)
    def __unicode__(self):
        return "%s (%s)" % (self.Description, self.Code)

class Son(models.Model):
    Father = models.ForeignKey(Father)
    Description = models.CharField(max_length=50)

And I want to create a filter by the select box shown to the user.

Assuming that I have a record in Father like:

  # |  Description | Code
--------------------------
  1 | Fred Nichols | 100

In the ForeignKey field should have a HTML content like:

<option value="1">Fred NIchols (100)</option>

if I try to query by the field in the son model:

Son.objects.filter(Father__Contains="Fred")

I get an error. In the documentation of Django the nearest option should be something like:

Son.objects.filter(Father__Description__contains="Fred")

or for any of the columns data

Son.objects.filter(Q(Father__Description__contains="Fred") | Q(Father__Code__Contains="Fred") )

I'd like to make something the most similar to the user info shown.

How could I make a query that could do that?

Answer 1

In single step u could do this :

Son.objects.filter(father__Description__contains="Fred")

you were doing it right the only thing that was wrong is :

the referencing entity Father should be lowercase name of the model

reference