你知道吗--------------------------------------------型号.PY--------------------------------------------你知道吗
class Artist(models.Model):
name = models.CharField("artist", max_length=50) #will display "artist" in front of artist-name
year_formed = models.PositiveIntegerField()
# Initialization Example
# newArtist = Artist(name = 'Artist Name', year_formed = 2015);
# newArtist.save();
# Album will be a foreign key
# Many to 1 relation ie (Single artist -> many albums)
class Album(models.Model):
name = models.CharField("album", max_length=50) #will display "album" in front of album-name
artist = models.ForeignKey(Artist)
------------------------------外壳------------------------------------------
newArtist = Artist(name = 'GBA',year_formed = 1990)
newArtist.save()
album1 = Album(name = 'a',artist = newArtist)
album2 = Album(name = 'b',artist = newArtist)
album3 = Album(name = 'c',artist = newArtist)
album1.save()
album2.save()
album3.save()
allAlbums = Album.objects.all()
for e in allAlbums:
print(e.artist.name)
---------------导致错误------------------
Traceback (most recent call last):
File "/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/site-packages/django/db/models/fields/related_descriptors.py", line 170, in __get__
rel_obj = getattr(instance, self.cache_name)
AttributeError: 'Album' object has no attribute '_artist_cache'
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
File "<input>", line 2, in <module>
File "/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/site-packages/django/db/models/fields/related_descriptors.py", line 179, in __get__
rel_obj = qs.get()
File "/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/site-packages/django/db/models/query.py", line 385, in get
self.model._meta.object_name
DB_start.models.DoesNotExist: Artist matching query does not exist.
我遵循正确的语法作为文档,但在错误的结果。如何成功访问外键字段?我也试过打印(e\uu name)。你知道吗
您的问题来自您设置的密钥的位置。你知道吗
这就是数据库的工作方式
-干杯
https://github.com/Ry10p/django-Plugis/blob/master/courses/models.py
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