在Django ORM中引用非主外键

How can I select entries in one table based on criteria in another table in Django's ORM if the foreign key is not referencing a primary key but another column with unique constraint?
The corresponding SQL command would be:

SELECT TableMoon.name
FROM TableMoon JOIN TablePlanet
ON TableMoon.planet = TablePlanet.name
WHERE classification = 'inner_planet';

预期的答案是:月球、火卫二、土卫二

我试图在Django ORM中从上面改写SQL命令，但每次都会得到一个空的QuerySet:

Tablemoon.objects.filter(planet__classification='inner_planet').values('name')
#Out: <QuerySet []>

Tablemoon.objects.filter(planet_id__classification='inner_planet').values('name')
#Out: <QuerySet []>

Background
I have a Django app that is connected to a legacy sqlite database. I am not allowed to modify the database scheme. The database looks like this:

TablePlanet  
------------------------------------  
planet_id |  name   | classification  
------------------------------------  
1         | Mercury | inner_planet  
2         | Venus   | inner_planet  
3         | Earth   | inner_planet  
4         | Mars    | inner_planet  
5         | Jupiter | outer_planet  
6         | Saturn  | outer_planet  
7         | Uranus  | outer_planet  
8         | Neptune | outer_planet  

TableMoon  
------------------------  
moon_id | planet  | name
------------------------  
1       | Earth   | Moon  
2       | Mars    | Phobos  
3       | Mars    | Deimos  
4       | Jupiter | Io  
5       | Jupiter | Europa  
6       | Jupiter | Ganymede  

列TablePlanet.name具有唯一约束.列TableMoon.planet具有引用TablePlanet.name的外键约束.

以下是这些表的SQL代码:

CREATE TABLE tablePlanet (
  planet_id INTEGER PRIMARY KEY,
  name TEXT UNIQUE NOT NULL,
  classification TEXT
);

CREATE TABLE tableMoon (
  moon_id INTEGER PRIMARY KEY,
  planet TEXT,
  name TEXT,
  FOREIGN KEY (planet) REFERENCES tablePlanet(name)
);

我的Models.py文件如下所示

from django.db import models


class Tableplanet(models.Model):
    planet_id = models.AutoField(primary_key=True, null=False)
    name = models.TextField(unique=True)
    classification = models.TextField(blank=True, null=True)

    class Meta:
        managed = False
        db_table = 'tablePlanet'


class Tablemoon(models.Model):
    moon_id = models.AutoField(primary_key=True, null=False)
    planet = models.ForeignKey('Tableplanet', models.DO_NOTHING,
                               db_column='planet', blank=True, null=True)
    name = models.TextField(blank=True, null=True)

    class Meta:
        managed = False
        db_table = 'tableMoon'

首先让我感到困惑的是Django对Planet-Column的命名，其中一种情况下是‘Planet’，另一种情况下是‘Planet_id’:

Tablemoon._meta.get_fields()
#Out: (<django.db.models.fields.AutoField: moon_id>,
#Out:  <django.db.models.fields.related.ForeignKey: planet>,
#Out:  <django.db.models.fields.TextField: name>)

Tablemoon.objects.all().values()[0]
#Out: {'moon_id': 1, 'planet_id': 'Earth', 'name': 'Moon'}

我非常感谢您在这方面的建议！