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In [1]: from exercises_app.models import Album, Band
In [2]: bands = Band.objects.all()
In [3]: Album.objects.create(title='sample3', year=1990, rate=5, band=bands[1])
Out[3]: <Album: Album object (1)>
In [4]: Album.objects.create(title='sample4', year=1990, rate=5, band=bands[0])
Out[4]: <Album: Album object (2)>
In [5]: Album.objects.create(title='sample5', year=1994, rate=2, band=bands[2])
Out[5]: <Album: Album object (3)>
In [6]: Album.objects.create(title='sample 6', year=1996, rate=5, band=bands[2])
Out[6]: <Album: Album object (4)>
In [7]: bands = Band.objects.all()
In [8]: print(dir(bands[2]))
['DoesNotExist', 'MultipleObjectsReturned', '__class__', '__delattr__', '__dict__', '__dir__', '__doc__', '__eq__', '__format__', '__ge__
', '__getattribute__', '__getstate__', '__gt__', '__hash__', '__init__', '__init_subclass__', '__le__', '__lt__', '__module__', '__ne__',
'__new__', '__reduce__', '__reduce_ex__', '__repr__', '__setattr__', '__setstate__', '__sizeof__', '__str__', '__subclasshook__', '__wea
kref__', '_check_column_name_clashes', '_check_constraints', '_check_default_pk', '_check_field_name_clashes', '_check_fields', '_check_i
d_field', '_check_index_together', '_check_indexes', '_check_local_fields', '_check_long_column_names', '_check_m2m_through_same_relation
ship', '_check_managers', '_check_model', '_check_model_name_db_lookup_clashes', '_check_ordering', '_check_property_name_related_field_a
ccessor_clashes', '_check_single_primary_key', '_check_swappable', '_check_unique_together', '_do_insert', '_do_update', '_get_FIELD_disp
lay', '_get_expr_references', '_get_next_or_previous_by_FIELD', '_get_next_or_previous_in_order', '_get_pk_val', '_get_unique_checks', '_
meta', '_perform_date_checks', '_perform_unique_checks', '_prepare_related_fields_for_save', '_save_parents', '_save_table', '_set_pk_val
', '_state', 'album_set', 'check', 'clean', 'clean_fields', 'date_error_message', 'delete', 'from_db', 'full_clean', 'genre', 'get_deferr
ed_fields', 'get_genre_display', 'id', 'name', 'objects', 'pk', 'prepare_database_save', 'refresh_from_db', 'save', 'save_base', 'seriali
zable_value', 'still_active', 'unique_error_message', 'validate_unique', 'year']
In [9]: print(bands[2].album_set)
exercises_app.Album.None
In [10]: print(bands[2].album_set.get())
---------------------------------------------------------------------------
MultipleObjectsReturned Traceback (most recent call last)
Cell In[10], line 1
----> 1 print(bands[2].album_set.get())
File D:\nauka\coderslab\sierpien\ONL_PYT_W_29_podstawy_django-main\project\venv\lib\site-packages\django\db\models\manager.py:85, in Base
Manager._get_queryset_methods.<locals>.create_method.<locals>.manager_method(self, *args, **kwargs)
84 def manager_method(self, *args, **kwargs):
---> 85 return getattr(self.get_queryset(), name)(*args, **kwargs)
File D:\nauka\coderslab\sierpien\ONL_PYT_W_29_podstawy_django-main\project\venv\lib\site-packages\django\db\models\query.py:443, in Query
Set.get(self, *args, **kwargs)
438 if not num:
439 raise self.model.DoesNotExist(
440 "%s matching query does not exist." %
441 self.model._meta.object_name
442 )
--> 443 raise self.model.MultipleObjectsReturned(
444 'get() returned more than one %s -- it returned %s!' % (
445 self.model._meta.object_name,
446 num if not limit or num < limit else 'more than %s' % (limit - 1),
447 )
448 )
MultipleObjectsReturned: get() returned more than one Album -- it returned 2!
In [11]: bands[2].album_set.get()
---------------------------------------------------------------------------
MultipleObjectsReturned Traceback (most recent call last)
Cell In[11], line 1
----> 1 bands[2].album_set.get()
File D:\nauka\coderslab\sierpien\ONL_PYT_W_29_podstawy_django-main\project\venv\lib\site-packages\django\db\models\manager.py:85, in Base
Manager._get_queryset_methods.<locals>.create_method.<locals>.manager_method(self, *args, **kwargs)
84 def manager_method(self, *args, **kwargs):
---> 85 return getattr(self.get_queryset(), name)(*args, **kwargs)
File D:\nauka\coderslab\sierpien\ONL_PYT_W_29_podstawy_django-main\project\venv\lib\site-packages\django\db\models\query.py:443, in Query
Set.get(self, *args, **kwargs)
438 if not num:
439 raise self.model.DoesNotExist(
440 "%s matching query does not exist." %
441 self.model._meta.object_name
442 )
--> 443 raise self.model.MultipleObjectsReturned(
444 'get() returned more than one %s -- it returned %s!' % (
445 self.model._meta.object_name,
446 num if not limit or num < limit else 'more than %s' % (limit - 1),
447 )
448 )
MultipleObjectsReturned: get() returned more than one Album -- it returned 2!
In [12]: bands[2].album_set.all()
Out[12]: <QuerySet [<Album: Album object (3)>, <Album: Album object (4)>]>
In [13]: [print(album.title) for album in bands[2].album_set.all()]
sample5
sample 6
Out[13]: [None, None]
In [14]: exit()
(venv) D:\nauka\coderslab\sierpien\ONL_PYT_W_29_podstawy_django-main\project>python manage.py makemigrations
Migrations for 'exercises_app':
exercises_app\migrations\0010_song.py
- Create model Song
(venv) D:\nauka\coderslab\sierpien\ONL_PYT_W_29_podstawy_django-main\project>python manage.py migrate
Operations to perform:
Apply all migrations: admin, auth, contenttypes, exercises_app, football, sessions
Running migrations:
Applying exercises_app.0010_song... OK
(venv) D:\nauka\coderslab\sierpien\ONL_PYT_W_29_podstawy_django-main\project>python manage.py shell
Python 3.9.0 (tags/v3.9.0:9cf6752, Oct 5 2020, 15:34:40) [MSC v.1927 64 bit (AMD64)]
Type 'copyright', 'credits' or 'license' for more information
IPython 8.14.0 -- An enhanced Interactive Python. Type '?' for help.
In [1]: from exercises_app.models import Album, Band, Song
In [2]: albums = Album.objects.all()
In [3]: Song.objects.create(title="song10", album=albums[0])
Out[3]: <Song: Song object (1)>
In [4]: Song.objects.create(title="song11", album=albums[0])
Out[4]: <Song: Song object (2)>
In [5]: Song.objects.create(title="song12", album=albums[0])
Out[5]: <Song: Song object (3)>
In [6]: Song.objects.create(title="song1", album=albums[1])
Out[6]: <Song: Song object (4)>
In [7]: Song.objects.create(title="song2", album=albums[1])
Out[7]: <Song: Song object (5)>
In [8]: Song.objects.create(title="song3", album=albums[1])
Out[8]: <Song: Song object (6)>
In [9]: bands = Band.objects.all()
In [10]: for band in bands:
...: albums = band.album_set.all()
...: if len(albums) > 0:
...: print("albums for band", band.name)
...: for album in albums:
...: print(" album:", album.title)
...:
albums for band Metallica
album: sample4
albums for band Pink Floyd
album: sample3
albums for band The Clash
album: sample5
album: sample 6
In [11]: albums = Album.objects.all()
In [12]: for album in albums:
...: print("album :", album.title)
...: songs = album.song_set.all()
...: for song in songs:
...: print(" song:", song.title)
...:
album : sample3
song: song10
song: song11
song: song12
album : sample4
song: song1
song: song2
song: song3
album : sample5
album : sample 6
In [13]: exit()
(venv) D:\nauka\coderslab\sierpien\ONL_PYT_W_29_podstawy_django-main\project>python manage.py makemigrations
Migrations for 'exercises_app':
exercises_app\migrations\0011_article_category.py
- Add field category to article
(venv) D:\nauka\coderslab\sierpien\ONL_PYT_W_29_podstawy_django-main\project>python manage.py migrate
Operations to perform:
Apply all migrations: admin, auth, contenttypes, exercises_app, football, sessions
Running migrations:
Applying exercises_app.0011_article_category... OK
(venv) D:\nauka\coderslab\sierpien\ONL_PYT_W_29_podstawy_django-main\project>python manage.py shell
Python 3.9.0 (tags/v3.9.0:9cf6752, Oct 5 2020, 15:34:40) [MSC v.1927 64 bit (AMD64)]
Type 'copyright', 'credits' or 'license' for more information
IPython 8.14.0 -- An enhanced Interactive Python. Type '?' for help.
In [1]: from exercises_app.models import Article, Category
In [2]: albums = Album.objects.all()
---------------------------------------------------------------------------
NameError Traceback (most recent call last)
Cell In[2], line 1
----> 1 albums = Album.objects.all()
NameError: name 'Album' is not defined
In [3]: from exercises_app.models import Article, Category
In [4]: articles = Article.objects.all()
In [5]: categories = Category.objects.all()
In [6]: print(categories[0].name)
ca1
In [7]: print(articles[0].title)
sample2
In [8]: articles[0].category.add(categories[0])
In [9]: articles[0].category.add(categories[1])
In [10]: dir(categories[1])
Out[10]:
['DoesNotExist',
'MultipleObjectsReturned',
'__class__',
'__delattr__',
'__dict__',
'__dir__',
'__doc__',
'__eq__',
'__format__',
'__ge__',
'__getattribute__',
'__getstate__',
'__gt__',
'__hash__',
'__init__',
'__init_subclass__',
'__le__',
'__lt__',
'__module__',
'__ne__',
'__new__',
'__reduce__',
'__reduce_ex__',
'__repr__',
'__setattr__',
'__setstate__',
'__sizeof__',
'__str__',
'__subclasshook__',
'__weakref__',
'_check_column_name_clashes',
'_check_constraints',
'_check_default_pk',
'_check_field_name_clashes',
'_check_fields',
'_check_id_field',
'_check_index_together',
'_check_indexes',
'_check_local_fields',
'_check_long_column_names',
'_check_m2m_through_same_relationship',
'_check_managers',
'_check_model',
'_check_model_name_db_lookup_clashes',
'_check_ordering',
'_check_property_name_related_field_accessor_clashes',
'_check_single_primary_key',
'_check_swappable',
'_check_unique_together',
'_do_insert',
'_do_update',
'_get_FIELD_display',
'_get_expr_references',
'_get_next_or_previous_by_FIELD',
'_get_next_or_previous_in_order',
'_get_pk_val',
'_get_unique_checks',
'_meta',
'_perform_date_checks',
'_perform_unique_checks',
'_prepare_related_fields_for_save',
'_save_parents',
'_save_table',
'_set_pk_val',
'_state',
'article_set',
'check',
'clean',
'clean_fields',
'date_error_message',
'delete',
'description',
'from_db',
'full_clean',
'get_deferred_fields',
'id',
'name',
'objects',
'pk',
'prepare_database_save',
'refresh_from_db',
'save',
'save_base',
'serializable_value',
'unique_error_message',
'validate_unique']
In [11]: categories[2].article_set.add(article[1])
---------------------------------------------------------------------------
NameError Traceback (most recent call last)
Cell In[11], line 1
----> 1 categories[2].article_set.add(article[1])
NameError: name 'article' is not defined
In [12]: categories[2].article_set.add(articles[1])