I have a pre-existing model that I am now trying to add an additional field too. It wasn't me that made the original field but I have been adding fields to other classes and making migrations fine.
I want to add an additional image field to the class Event, there is already an image field on this class so I know it can handle image fields, I have tried changing the name around to see if that was a issue too. Here is the field I want to add:
social_media_image = models.ImageField(null=True, blank=True, help_text='Hello World')
This is the error I get when i'm trying to make my migration after adding that code to the model:
django.db.utils.OperationalError: no such column: posts_event.social_media_image
From my understanding of how migrations work there shouldn't be a column called this yet as I haven't made the migration yet that will add it to the DB.
I have tried adding a default value to the field as well but with no luck. I have also tried completely removing the DB along with migration files and trying to recreate them.
Here are the rest of the fields in the model:
slug = AutoSlugField(max_length=50, unique=True, populate_from='title')
content = models.TextField(default='')
start_time = models.DateTimeField()
image = models.ImageField(null=True, blank=True, help_text=image_help_text)
Here is the traceback:
Traceback (most recent call last):
File "/Applications/XAMPP/xamppfiles/htdocs/enfield/enfield-presents/venv/lib/python3.4/site-packages/django/db/backends/utils.py", line 64, in execute
return self.cursor.execute(sql, params)
File "/Applications/XAMPP/xamppfiles/htdocs/enfield/enfield-presents/venv/lib/python3.4/site-packages/django/db/backends/sqlite3/base.py", line 337, in execute
return Database.Cursor.execute(self, query, params)
sqlite3.OperationalError: no such column: posts_event.social_media_image
The above exception was the direct cause of the following exception:
Traceback (most recent call last):
File "manage.py", line 22, in <module>
execute_from_command_line(sys.argv)
File "/Applications/XAMPP/xamppfiles/htdocs/enfield/enfield-presents/venv/lib/python3.4/site-packages/django/core/management/__init__.py", line 367, in execute_from_command_line
utility.execute()
File "/Applications/XAMPP/xamppfiles/htdocs/enfield/enfield-presents/venv/lib/python3.4/site-packages/django/core/management/__init__.py", line 341, in execute
django.setup()
File "/Applications/XAMPP/xamppfiles/htdocs/enfield/enfield-presents/venv/lib/python3.4/site-packages/django/__init__.py", line 27, in setup
apps.populate(settings.INSTALLED_APPS)
File "/Applications/XAMPP/xamppfiles/htdocs/enfield/enfield-presents/venv/lib/python3.4/site-packages/django/apps/registry.py", line 115, in populate
app_config.ready()
File "/Applications/XAMPP/xamppfiles/htdocs/enfield/enfield-presents/source/enfield_presents/posts/apps.py", line 37, in ready
search.register(Event.objects.get_upcoming_events(site_id=settings.SITE_ID, include_spektrix=False, return_queryset=True))
File "/Applications/XAMPP/xamppfiles/htdocs/enfield/enfield-presents/source/enfield_presents/posts/models.py", line 282, in get_upcoming_events
events_with_a_next_start_time = [e for e in events if e.next_start_time() is not None]
File "/Applications/XAMPP/xamppfiles/htdocs/enfield/enfield-presents/venv/lib/python3.4/site-packages/django/db/models/query.py", line 256, in __iter__
self._fetch_all()
File "/Applications/XAMPP/xamppfiles/htdocs/enfield/enfield-presents/venv/lib/python3.4/site-packages/django/db/models/query.py", line 1087, in _fetch_all
self._result_cache = list(self.iterator())
File "/Applications/XAMPP/xamppfiles/htdocs/enfield/enfield-presents/venv/lib/python3.4/site-packages/django/db/models/query.py", line 54, in __iter__
results = compiler.execute_sql()
File "/Applications/XAMPP/xamppfiles/htdocs/enfield/enfield-presents/venv/lib/python3.4/site-packages/django/db/models/sql/compiler.py", line 835, in execute_sql
cursor.execute(sql, params)
File "/Applications/XAMPP/xamppfiles/htdocs/enfield/enfield-presents/venv/lib/python3.4/site-packages/django/db/backends/utils.py", line 79, in execute
return super(CursorDebugWrapper, self).execute(sql, params)
File "/Applications/XAMPP/xamppfiles/htdocs/enfield/enfield-presents/venv/lib/python3.4/site-packages/django/db/backends/utils.py", line 64, in execute
return self.cursor.execute(sql, params)
File "/Applications/XAMPP/xamppfiles/htdocs/enfield/enfield-presents/venv/lib/python3.4/site-packages/django/db/utils.py", line 94, in __exit__
six.reraise(dj_exc_type, dj_exc_value, traceback)
File "/Applications/XAMPP/xamppfiles/htdocs/enfield/enfield-presents/venv/lib/python3.4/site-packages/django/utils/six.py", line 685, in reraise
raise value.with_traceback(tb)
File "/Applications/XAMPP/xamppfiles/htdocs/enfield/enfield-presents/venv/lib/python3.4/site-packages/django/db/backends/utils.py", line 64, in execute
return self.cursor.execute(sql, params)
File "/Applications/XAMPP/xamppfiles/htdocs/enfield/enfield-presents/venv/lib/python3.4/site-packages/django/db/backends/sqlite3/base.py", line 337, in execute
return Database.Cursor.execute(self, query, params)
django.db.utils.OperationalError: no such column: posts_event.social_media_image
This issue may be due to the reason that the corresponding Image field may not be present in the database. Please login to the database shell and check whether the corresponding field is there. If it is not there add it manually using SQL query or rollback to a previous safe migration and then make the changes in models.py and generate the migration files.
It's right there:
File "/Applications/XAMPP/xamppfiles/htdocs/enfield/enfield-presents/source/enfield_presents/posts/apps.py", line 37, in ready:
search.register(Event.objects.get_upcoming_events(site_id=settings.SITE_ID, include_spektrix=False, return_queryset=True))
You do a queryset on the source of one app, that as far as I can tell, queries the model of the other app. You shouldn't do queries in app setup if you can avoid it. Use signals if you have to or lazy loading.
If you really have to, then flip the order of the apps. If it's the same app, then yes, don't do it: as you notice, you won't be able to do any migrations.
Related
I am not sure whether I am doing something wrong or it is a problem with one of the pieces I am using for the project.
Basically, I added a field to a model and am trying to make a migration.
Here is the model. The field is the poster one.
class Video(models.Model):
title=models.CharField(max_length=500)
description=models.TextField(default="")
creation_date=models.DateTimeField(default=timezone.now)
videofile=models.FileField(upload_to='videos/', null=True, verbose_name="")
poster=models.ImageField(upload_to='video/thumbnails', null=True, verbose_name="")
tags = TaggableManager()
actions = ['delete']
def __str__(self):
return self.title + ": " + str(self.videofile)
...
That is the only thing that changed in the model. Let's make the migrations.
(app-web) selfishman#user-desktop:~/sites/app-web/app$ python manage.py makemigrations
Migrations for 'video_uploader':
video_uploader/migrations/0007_video_poster.py
- Add field poster to video
So far, so good. Let's try to apply the migration.
(app-web) user#user-desktop:~/sites/app-web/app$ python manage.py migrate video_uploader
Operations to perform:
Apply all migrations: video_uploader
Running migrations:
Applying video_uploader.0002_video_creation_date...Traceback (most recent call last):
File "/home/user/miniconda3/envs/app-web/lib/python3.7/site-packages/django/db/backends/ut
ils.py", line 85, in _execute
return self.cursor.execute(sql, params)
psycopg2.errors.DuplicateColumn: column "creation_date" of relation "video_uploader_video" already exists
There rest of the backtrace:
The above exception was the direct cause of the following exception:
Traceback (most recent call last):
File "manage.py", line 20, in <module>
execute_from_command_line(sys.argv)
File "/home/user/miniconda3/envs/app-web/lib/python3.7/site-packages/django/core/managemen
t/__init__.py", line 381, in execute_from_command_line
utility.execute()
File "/home/user/miniconda3/envs/app-web/lib/python3.7/site-packages/django/core/managemen
t/__init__.py", line 375, in execute
self.fetch_command(subcommand).run_from_argv(self.argv)
File "/home/user/miniconda3/envs/app-web/lib/python3.7/site-packages/django/core/managemen
t/base.py", line 316, in run_from_argv
self.execute(*args, **cmd_options)
File "/home/user/miniconda3/envs/app-web/lib/python3.7/site-packages/django/core/managemen
t/base.py", line 353, in execute
output = self.handle(*args, **options)
File "/home/user/miniconda3/envs/app-web/lib/python3.7/site-packages/django/core/managemen
t/base.py", line 83, in wrapped
res = handle_func(*args, **kwargs)
File "/home/user/miniconda3/envs/app-web/lib/python3.7/site-packages/django/core/managemen
t/commands/migrate.py", line 203, in handle
fake_initial=fake_initial,
File "/home/user/miniconda3/envs/app-web/lib/python3.7/site-packages/django/db/migrations/
executor.py", line 117, in migrate
state = self._migrate_all_forwards(state, plan, full_plan, fake=fake, fake_initial=fake_initial)
File "/home/user/miniconda3/envs/app-web/lib/python3.7/site-packages/django/db/migrations/
executor.py", line 147, in _migrate_all_forwards
state = self.apply_migration(state, migration, fake=fake, fake_initial=fake_initial)
File "/home/user/miniconda3/envs/app-web/lib/python3.7/site-packages/django/db/migrations/
executor.py", line 244, in apply_migration
state = migration.apply(state, schema_editor)
File "/home/user/miniconda3/envs/app-web/lib/python3.7/site-packages/django/db/migrations/
migration.py", line 124, in apply
operation.database_forwards(self.app_label, schema_editor, old_state, project_state)
File "/home/user/miniconda3/envs/app-web/lib/python3.7/site-packages/django/db/migrations/
operations/fields.py", line 84, in database_forwards
field,
File "/home/user/miniconda3/envs/app-web/lib/python3.7/site-packages/django/db/backends/ba
se/schema.py", line 435, in add_field
self.execute(sql, params)
File "/home/user/miniconda3/envs/app-web/lib/python3.7/site-packages/django/db/backends/ba
se/schema.py", line 133, in execute
cursor.execute(sql, params)
File "/home/user/miniconda3/envs/app-web/lib/python3.7/site-packages/django/db/backends/ut
ils.py", line 100, in execute
return super().execute(sql, params)
File "/home/user/miniconda3/envs/app-web/lib/python3.7/site-packages/django/db/backends/ut
ils.py", line 68, in execute
return self._execute_with_wrappers(sql, params, many=False, executor=self._execute)
File "/home/user/miniconda3/envs/app-web/lib/python3.7/site-packages/django/db/backends/ut
ils.py", line 77, in _execute_with_wrappers
return executor(sql, params, many, context)
File "/home/user/miniconda3/envs/app-web/lib/python3.7/site-packages/django/db/backends/ut
ils.py", line 85, in _execute
return self.cursor.execute(sql, params)
File "/home/user/miniconda3/envs/app-web/lib/python3.7/site-packages/django/db/utils.py",
line 89, in __exit__
raise dj_exc_value.with_traceback(traceback) from exc_value
File "/home/user/miniconda3/envs/app-web/lib/python3.7/site-packages/django/db/backends/ut
ils.py", line 85, in _execute
return self.cursor.execute(sql, params)
django.db.utils.ProgrammingError: column "creation_date" of relation "video_uploader_video" already exists
This is the migration that was created:
from django.db import migrations, models
class Migration(migrations.Migration):
dependencies = [
('video_uploader', '0006_video_description'),
]
operations = [
migrations.AddField(
model_name='video',
name='poster',
field=models.ImageField(null=True, upload_to='video/thumbnails', verbose_name=''),
),
]
Could someone tell me what is going on here? I am using Postgres 12. When I run tests, and an (SQLite) DB is created from scratch, there is no such error.
Any help is appreciated.
P.S. We have seen quite a few inconsistencies when it comes to Django migrations and Postgres/Psycopg2. Not sure if something is up with the config or versions/dependencies.
You created a new migration and it was named
0007_video_poster
However when you run the migrate it is running
0002_video_creation_date
And this is trying to create a new column named creation_date however that's already there.
You are getting inconsistent results because django thinks the previous migrations were not applied and therefore it is trying to apply them.
The easiest way would be to flush the database (make sure you first export any data you might need) using
python manage.py flush
This would reset the database and then you can run the migrations normally and it should work fine.
Otherwise if you want to execute the migration you just created i.e. 0007_video_poster
You can run this
python manage.py migrate video_uploader 0007_video_poster
I am using Django shell for debug purpose of my project by using command python manage.py shell.
I have found that I am not able to execute ORM queries from shell & getting below kind of error.
from base.models import Template_Form, Template_Form_Field
Template_Form_Field.objects.all()
After executing above code in shell I am getting below error.
Traceback (most recent call last):
File "D:\production\siralo\siralo_py3\venv\lib\site-packages\django\db\backends\utils.py", line 84, in _execute
return self.cursor.execute(sql, params)
psycopg2.errors.UndefinedTable: relation "base_template_form_field" does not exist
LINE 1: ...ions", "base_template_form_field"."sequence" FROM "base_temp...
^
The above exception was the direct cause of the following exception:
Traceback (most recent call last):
File "<console>", line 1, in <module>
File "D:\production\siralo\siralo_py3\venv\lib\site-packages\django\db\models\query.py", line 250, in __repr__
data = list(self[:REPR_OUTPUT_SIZE + 1])
File "D:\production\siralo\siralo_py3\venv\lib\site-packages\django\db\models\query.py", line 274, in __iter__
self._fetch_all()
File "D:\production\siralo\siralo_py3\venv\lib\site-packages\django\db\models\query.py", line 1242, in _fetch_all
self._result_cache = list(self._iterable_class(self))
File "D:\production\siralo\siralo_py3\venv\lib\site-packages\django\db\models\query.py", line 55, in __iter__
results = compiler.execute_sql(chunked_fetch=self.chunked_fetch, chunk_size=self.chunk_size)
File "D:\production\siralo\siralo_py3\venv\lib\site-packages\django\db\models\sql\compiler.py", line 1100, in execute_sql
cursor.execute(sql, params)
File "D:\production\siralo\siralo_py3\venv\lib\site-packages\django\db\backends\utils.py", line 99, in execute
return super().execute(sql, params)
File "D:\production\siralo\siralo_py3\venv\lib\site-packages\django\db\backends\utils.py", line 67, in execute
return self._execute_with_wrappers(sql, params, many=False, executor=self._execute)
File "D:\production\siralo\siralo_py3\venv\lib\site-packages\django\db\backends\utils.py", line 76, in _execute_with_wrappers
return executor(sql, params, many, context)
File "D:\production\siralo\siralo_py3\venv\lib\site-packages\django\db\backends\utils.py", line 84, in _execute
return self.cursor.execute(sql, params)
File "D:\production\siralo\siralo_py3\venv\lib\site-packages\django\db\utils.py", line 89, in __exit__
raise dj_exc_value.with_traceback(traceback) from exc_value
File "D:\production\siralo\siralo_py3\venv\lib\site-packages\django\db\backends\utils.py", line 84, in _execute
return self.cursor.execute(sql, params)
django.db.utils.ProgrammingError: relation "base_template_form_field" does not exist
LINE 1: ...ions", "base_template_form_field"."sequence" FROM "base_temp...
Does anybody have idea why am I getting above error & how to get rid of it.
I have tried to search on google but not able to find any solution.
Template form field model is as below.
class Template_Form_Field(models.Model):
template_form = models.ForeignKey(Template_Form, on_delete=models.CASCADE)
name = models.CharField(max_length=40, verbose_name='Name')
caption = models.CharField(max_length=80, verbose_name='Caption')
value_options = models.TextField(null=True, blank=True, verbose_name='Value options')
sequence = models.IntegerField(blank=True, null=True, verbose_name='Sequence')
Thanks.
just run python manage.py migrate
this error is because you have just run python manage.py makemigrations but did'nt run python manage.py migrate.
i also encounter the same error in shell while i have not run the migrate command below is the screen shot of error i get this is the screenshot of the same error
I recently started a django project and I am having trouble accessing a sqlite3 database that I recently added. I ran python manage.py inspectdb --database 'football' after inserting the new database into settings.py. This gave me the file that I copy pasted into models.py. From there I ran makemigrations which gave me this error:
SystemCheckError: System check identified some issues:
ERRORS:
teambuilder.Countries.country_id: (fields.E007) Primary keys must not have null=True.
HINT: Set null=False on the field, or remove primary_key=True argument.
teambuilder.Playertransferhistory: (models.E004) 'id' can only be used as a field name if the field also sets 'primary_key=True'.
teambuilder.Teams.team_id: (fields.E007) Primary keys must not have null=True.
HINT: Set null=False on the field, or remove primary_key=True argument.
(venv) Jacks-MBP:SportWebsite Tilley$ python manage.py makemigrations
SystemCheckError: System check identified some issues:
ERRORS:
teambuilder.Playertransferhistory.id: (fields.E007) Primary keys must not have null=True.
HINT: Set null=False on the field, or remove primary_key=True argument.
From there I changed null to false where needed and reran makemigrations
which gave me this:
Migrations for 'teambuilder':
teambuilder/migrations/0001_initial.py
- Create model Countries
- Create model LeagueGames
- Create model Leagues
- Create model Playerinfo
- Create model Playertransferhistory
- Create model Teams
followed by migrate which outputted:
Operations to perform:
Apply all migrations: admin, auth, contenttypes, sessions, sites, teambuilder
Running migrations:
No migrations to apply.
I then ran python manage.py shell and typed in the following commands:
from teambuilder.models import *
Leagues.objects.all()
which presented me with this red wall:
Traceback (most recent call last):
File "/Users/Tilley/PycharmProjects/SportWeb/venv/lib/python3.6/site-packages/django/db/backends/utils.py", line 85, in _execute
return self.cursor.execute(sql, params)
File "/Users/Tilley/PycharmProjects/SportWeb/venv/lib/python3.6/site-packages/django/db/backends/sqlite3/base.py", line 298, in execute
return Database.Cursor.execute(self, query, params)
sqlite3.OperationalError: no such table: Leagues
The above exception was the direct cause of the following exception:
Traceback (most recent call last):
File "<console>", line 1, in <module>
File "/Users/Tilley/PycharmProjects/SportWeb/venv/lib/python3.6/site-packages/django/db/models/query.py", line 244, in __repr__
data = list(self[:REPR_OUTPUT_SIZE + 1])
File "/Users/Tilley/PycharmProjects/SportWeb/venv/lib/python3.6/site-packages/django/db/models/query.py", line 268, in __iter__
self._fetch_all()
File "/Users/Tilley/PycharmProjects/SportWeb/venv/lib/python3.6/site-packages/django/db/models/query.py", line 1186, in _fetch_all
self._result_cache = list(self._iterable_class(self))
File "/Users/Tilley/PycharmProjects/SportWeb/venv/lib/python3.6/site-packages/django/db/models/query.py", line 54, in __iter__
results = compiler.execute_sql(chunked_fetch=self.chunked_fetch, chunk_size=self.chunk_size)
File "/Users/Tilley/PycharmProjects/SportWeb/venv/lib/python3.6/site-packages/django/db/models/sql/compiler.py", line 1065, in execute_sql
cursor.execute(sql, params)
File "/Users/Tilley/PycharmProjects/SportWeb/venv/lib/python3.6/site-packages/django/db/backends/utils.py", line 100, in execute
return super().execute(sql, params)
File "/Users/Tilley/PycharmProjects/SportWeb/venv/lib/python3.6/site-packages/django/db/backends/utils.py", line 68, in execute
return self._execute_with_wrappers(sql, params, many=False, executor=self._execute)
File "/Users/Tilley/PycharmProjects/SportWeb/venv/lib/python3.6/site-packages/django/db/backends/utils.py", line 77, in _execute_with_wrappers
return executor(sql, params, many, context)
File "/Users/Tilley/PycharmProjects/SportWeb/venv/lib/python3.6/site-packages/django/db/backends/utils.py", line 85, in _execute
return self.cursor.execute(sql, params)
File "/Users/Tilley/PycharmProjects/SportWeb/venv/lib/python3.6/site-packages/django/db/utils.py", line 89, in __exit__
raise dj_exc_value.with_traceback(traceback) from exc_value
File "/Users/Tilley/PycharmProjects/SportWeb/venv/lib/python3.6/site-packages/django/db/backends/utils.py", line 85, in _execute
return self.cursor.execute(sql, params)
File "/Users/Tilley/PycharmProjects/SportWeb/venv/lib/python3.6/site-packages/django/db/backends/sqlite3/base.py", line 298, in execute
return Database.Cursor.execute(self, query, params)
django.db.utils.OperationalError: no such table: Leagues
I know that the table does exist but I cannot understand why I'm getting this error. I've seen similar questions here on SO but none of the solutions have fixed my problem. Any help would be greatly appreciated.
I am unable to run makemigrations, migrate, or anything else (flush, reset_db from django-extensions) if I have a certain app in my INSTALLED_APPS.
The app is called issues and has one model:
class Issue(models.Model):
title = models.CharField(max_length=255)
description = models.CharField(max_length=1000)
sent = models.BooleanField()
And it was working before (makemigrations and migrate ran fine and I could use the app/model correctly), until I tried adding:
severity = models.IntegerField()
and tried to run makemigrations. I don't have the error or remember it anymore, but since then everything is broken, even after removing severity from the model.
Everything works if I remove the issues app from my settings.py.
The error I get:
madjura#madjura-E6228:~/workspace/budget/src$ python3.5 manage.py makemigrationsTraceback (most recent call last):
File "/usr/local/lib/python3.5/dist-packages/django/db/backends/utils.py", line 64, in execute
return self.cursor.execute(sql, params)
File "/usr/local/lib/python3.5/dist-packages/django/db/backends/sqlite3/base.py", line 337, in execute
return Database.Cursor.execute(self, query, params)
sqlite3.OperationalError: no such table: issues_issue
The above exception was the direct cause of the following exception:
Traceback (most recent call last):
File "manage.py", line 22, in <module>
execute_from_command_line(sys.argv)
File "/usr/local/lib/python3.5/dist-packages/django/core/management/__init__.py", line 367, in execute_from_command_line
utility.execute()
File "/usr/local/lib/python3.5/dist-packages/django/core/management/__init__.py", line 341, in execute
django.setup()
File "/usr/local/lib/python3.5/dist-packages/django/__init__.py", line 27, in setup
apps.populate(settings.INSTALLED_APPS)
File "/usr/local/lib/python3.5/dist-packages/django/apps/registry.py", line 115, in populate
app_config.ready()
File "/home/madjura/workspace/budget/src/issues/apps.py", line 16, in ready
issues.models.Issue.objects.check_and_send_unsent_issues()
File "/home/madjura/workspace/budget/src/issues/models.py", line 18, in check_and_send_unsent_issues
for issue in issues:
File "/usr/local/lib/python3.5/dist-packages/django/db/models/query.py", line 256, in __iter__
self._fetch_all()
File "/usr/local/lib/python3.5/dist-packages/django/db/models/query.py", line 1087, in _fetch_all
self._result_cache = list(self.iterator())
File "/usr/local/lib/python3.5/dist-packages/django/db/models/query.py", line 54, in __iter__
results = compiler.execute_sql()
File "/usr/local/lib/python3.5/dist-packages/django/db/models/sql/compiler.py", line 835, in execute_sql
cursor.execute(sql, params)
File "/usr/local/lib/python3.5/dist-packages/django/db/backends/utils.py", line 79, in execute
return super(CursorDebugWrapper, self).execute(sql, params)
File "/usr/local/lib/python3.5/dist-packages/django/db/backends/utils.py", line 64, in execute
return self.cursor.execute(sql, params)
File "/usr/local/lib/python3.5/dist-packages/django/db/utils.py", line 94, in __exit__
six.reraise(dj_exc_type, dj_exc_value, traceback)
File "/usr/local/lib/python3.5/dist-packages/django/utils/six.py", line 685, in reraise
raise value.with_traceback(tb)
File "/usr/local/lib/python3.5/dist-packages/django/db/backends/utils.py", line 64, in execute
return self.cursor.execute(sql, params)
File "/usr/local/lib/python3.5/dist-packages/django/db/backends/sqlite3/base.py", line 337, in execute
return Database.Cursor.execute(self, query, params)
django.db.utils.OperationalError: no such table: issues_issue
While issues is in INSTALLED_APPS I get the same error when running migrate, flush and reset_db.
I have tried running flush and reset_db with issues removed from INSTALLED_APPS, this did not solve the problem.
I have tried doing the above and then running makemigrations and migrate, this does also not work. As soon as I put issues back in INSTALLED_APPS everything is broken.
How can I fix this?
EDIT:
Maybe relevant, the issue model has a Manager with a function:
class IssueManager(models.Manager):
"""Manager for the Issue class."""
def check_and_send_unsent_issues(self):
"""
Checks for unsent Issue objects (Issue.sent = False) and attempts
to send them.
Issues that have been sent are deleted.
If the issue fails to be sent for whatever reason, it is not deleted.
Does nothing if there are no unsent issues.
This method is called once when the server starts.
"""
issues = self.get_queryset().filter(sent=False)
for issue in issues:
try:
make_issue(issue.title, issue.description)
issue.delete()
except PostIssueException:
pass
Using apps.py I check for unsent issues and post them on Gitlab.
EDIT 2:
Issue resolved by commenting the line below which appears in my apps.py, in ready():
issues.models.Issue.objects.check_and_send_unsent_issues()
Which somehow caused things to break, I don't understand why. Could someone explain that please?
Try moving the line import issues.models into def ready() to prevent loading the models too early.
How do I catch an exception in a Django migration?
I have a migration that, because of various legacy reasons, I expect to fail sometimes. I want to be able to catch that error and run some error handling code in that case.
Specifically, I'm renaming a table, and sometimes the destination table already exists and I want to merge the contents of the old and new tables, then delete the old one.
I'm running Django 1.7 ( :( ) and we're planning on upgrading to 1.8 but it hasn't happened yet.
My migration is:
# -*- coding: utf-8 -*-
from __future__ import unicode_literals
from django.db import models, migrations
class Migration(migrations.Migration):
dependencies = [
('main', '0007_migration_name'),
]
operations = [
migrations.AlterModelTable(
name='table_name',
table='LegacyTableName',
),
]
When I run this, I get
Traceback (most recent call last):
File "manage.py", line 10, in <module>
execute_from_command_line(sys.argv)
File ".../django/core/management/__init__.py", line 385, in execute_from_command_line
utility.execute()
File ".../django/core/management/__init__.py", line 377, in execute
self.fetch_command(subcommand).run_from_argv(self.argv)
File ".../django/core/management/base.py", line 288, in run_from_argv
self.execute(*args, **options.__dict__)
File ".../django/core/management/base.py", line 338, in execute
output = self.handle(*args, **options)
File ".../django/core/management/commands/migrate.py", line 161, in handle
executor.migrate(targets, plan, fake=options.get("fake", False))
File ".../django/db/migrations/executor.py", line 68, in migrate
self.apply_migration(migration, fake=fake)
File ".../django/db/migrations/executor.py", line 102, in apply_migration
migration.apply(project_state, schema_editor)
File ".../django/db/migrations/migration.py", line 108, in apply
operation.database_forwards(self.app_label, schema_editor, project_state, new_state)
File ".../django/db/migrations/operations/models.py", line 236, in database_forwards
new_model._meta.db_table,
File ".../django/db/backends/schema.py", line 350, in alter_db_table
"new_table": self.quote_name(new_db_table),
File ".../django/db/backends/schema.py", line 111, in execute
cursor.execute(sql, params)
File ".../django/db/backends/utils.py", line 81, in execute
return super(CursorDebugWrapper, self).execute(sql, params)
File ".../django/db/backends/utils.py", line 65, in execute
return self.cursor.execute(sql, params)
File ".../django/db/utils.py", line 94, in __exit__
six.reraise(dj_exc_type, dj_exc_value, traceback)
File ".../django/db/backends/utils.py", line 65, in execute
return self.cursor.execute(sql, params)
File ".../django/db/backends/mysql/base.py", line 129, in execute
return self.cursor.execute(query, args)
File ".../MySQLdb/cursors.py", line 226, in execute
self.errorhandler(self, exc, value)
File ".../MySQLdb/connections.py", line 36, in defaulterrorhandler
raise errorvalue
django.db.utils.OperationalError: (1050, "Table 'LegacyTableName' already exists")
All that's provided in the migration itself is the operations list, and there doesn't seem to be an optional error-handling parameter in the docs.
How do I catch the OperationalError so I can run some Python to merge the tables?
The problem with trying to catch database exceptions in Python is that they may not be specific enough - e.g., OperationalError could arise for various reasons (only one of which is that the table name has already been changed).
I would suggest that rather than trying to catch exceptions you write your own migration function that does whatever checks/modifications are necessary. See the documentation on RunPython.
This is generally the operation you would use to create data migrations, run custom data updates and alterations, and anything else you need access to an ORM and/or Python code for.
In your case you would write a function that checks whether the table exists and performs some actions for either case.
There are some database-specific issues to be aware of when writing these functions, e.g., :
on PostgreSQL, for example, you should avoid combining schema changes and RunPython operations in the same migration or you may hit errors.