We Keep Coding

Django Migration timed out

I have a logging table,which is being continuously written to,in which i want to add a column,it's migration works fine on local but it's getting timed out on deployment
This is the migration file a have:
from django.db import migrations, models
class Migration(migrations.Migration):
dependencies = [
("request_log", "0004_requestlog2"),
]
operations = [
migrations.AddField(
model_name="requestlog2",
name="request_type",
field=models.PositiveSmallIntegerField(
blank=True,
choices=[(0, "Incoming"), (1, "Outgoing"), (2, "Internal")],
help_text="State the type on request",
null=True,
),
),
]
This is the migration logs:
Rendering model states... DONE
Applying request_log.0005_requestlog2_request_type...django 21/Oct/2022:15:12:54,194347 +0000 [INFO] squadrun.sentry_helpers: thread=140715699507328 extra: exchash: b8ca65d21d0d448f8fe90658c0708923 detected
Traceback (most recent call last):
File "/storage/.pyenv/versions/3.5.9/envs/squadrun_python3.5/lib/python3.5/site-packages/django/db/backends/utils.py", line 64, in execute
return self.cursor.execute(sql, params)
File "/storage/.pyenv/versions/3.5.9/envs/squadrun_python3.5/lib/python3.5/site-packages/elasticapm/instrumentation/packages/dbapi2.py", line 210, in execute
return self._trace_sql(self.__wrapped__.execute, sql, params)
File "/storage/.pyenv/versions/3.5.9/envs/squadrun_python3.5/lib/python3.5/site-packages/elasticapm/instrumentation/packages/dbapi2.py", line 244, in _trace_sql
result = method(sql, params)
psycopg2.extensions.QueryCanceledError: canceling statement due to statement timeout
The above exception was the direct cause of the following exception:
Traceback (most recent call last):
File "manage.py", line 40, in <module>
execute_from_command_line(sys.argv)
File "/storage/.pyenv/versions/3.5.9/envs/squadrun_python3.5/lib/python3.5/site-packages/django/core/management/__init__.py", line 353, in execute_from_command_line
utility.execute()
File "/storage/.pyenv/versions/3.5.9/envs/squadrun_python3.5/lib/python3.5/site-packages/django/core/management/__init__.py", line 345, in execute
self.fetch_command(subcommand).run_from_argv(self.argv)
File "/storage/.pyenv/versions/3.5.9/envs/squadrun_python3.5/lib/python3.5/site-packages/django/core/management/base.py", line 348, in run_from_argv
self.execute(*args, **cmd_options)
File "/storage/.pyenv/versions/3.5.9/envs/squadrun_python3.5/lib/python3.5/site-packages/django/core/management/base.py", line 399, in execute
output = self.handle(*args, **options)
File "/storage/.pyenv/versions/3.5.9/envs/squadrun_python3.5/lib/python3.5/site-packages/django/core/management/commands/migrate.py", line 200, in handle
executor.migrate(targets, plan, fake=fake, fake_initial=fake_initial)
File "/storage/.pyenv/versions/3.5.9/envs/squadrun_python3.5/lib/python3.5/site-packages/django/db/migrations/executor.py", line 92, in migrate
self._migrate_all_forwards(plan, full_plan, fake=fake, fake_initial=fake_initial)
File "/storage/.pyenv/versions/3.5.9/envs/squadrun_python3.5/lib/python3.5/site-packages/django/db/migrations/executor.py", line 121, in _migrate_all_forwards
state = self.apply_migration(state, migration, fake=fake, fake_initial=fake_initial)
File "/storage/.pyenv/versions/3.5.9/envs/squadrun_python3.5/lib/python3.5/site-packages/django/db/migrations/executor.py", line 198, in apply_migration
state = migration.apply(state, schema_editor)
File "/storage/.pyenv/versions/3.5.9/envs/squadrun_python3.5/lib/python3.5/site-packages/django/db/migrations/migration.py", line 123, in apply
operation.database_forwards(self.app_label, schema_editor, old_state, project_state)
File "/storage/.pyenv/versions/3.5.9/envs/squadrun_python3.5/lib/python3.5/site-packages/django/db/migrations/operations/fields.py", line 62, in database_forwards
field,
File "/storage/.pyenv/versions/3.5.9/envs/squadrun_python3.5/lib/python3.5/site-packages/django/contrib/gis/db/backends/postgis/schema.py", line 69, in add_field
super(PostGISSchemaEditor, self).add_field(model, field)
File "/storage/.pyenv/versions/3.5.9/envs/squadrun_python3.5/lib/python3.5/site-packages/django/db/backends/base/schema.py", line 396, in add_field
self.execute(sql, params)
File "/storage/.pyenv/versions/3.5.9/envs/squadrun_python3.5/lib/python3.5/site-packages/django/db/backends/base/schema.py", line 110, in execute
cursor.execute(sql, params)
File "/storage/.pyenv/versions/3.5.9/envs/squadrun_python3.5/lib/python3.5/site-packages/sentry_sdk/integrations/django/__init__.py", line 446, in execute
return real_execute(self, sql, params)
File "/storage/.pyenv/versions/3.5.9/envs/squadrun_python3.5/lib/python3.5/site-packages/django/db/backends/utils.py", line 64, in execute
return self.cursor.execute(sql, params)
File "/storage/.pyenv/versions/3.5.9/envs/squadrun_python3.5/lib/python3.5/site-packages/django/db/utils.py", line 95, in __exit__
six.reraise(dj_exc_type, dj_exc_value, traceback)
File "/storage/.pyenv/versions/3.5.9/envs/squadrun_python3.5/lib/python3.5/site-packages/django/utils/six.py", line 685, in reraise
raise value.with_traceback(tb)
File "/storage/.pyenv/versions/3.5.9/envs/squadrun_python3.5/lib/python3.5/site-packages/django/db/backends/utils.py", line 64, in execute
return self.cursor.execute(sql, params)
File "/storage/.pyenv/versions/3.5.9/envs/squadrun_python3.5/lib/python3.5/site-packages/elasticapm/instrumentation/packages/dbapi2.py", line 210, in execute
return self._trace_sql(self.__wrapped__.execute, sql, params)
File "/storage/.pyenv/versions/3.5.9/envs/squadrun_python3.5/lib/python3.5/site-packages/elasticapm/instrumentation/packages/dbapi2.py", line 244, in _trace_sql
result = method(sql, params)
django.db.utils.OperationalError: canceling statement due to statement timeout
Sentry is attempting to send 0 pending error messages
Waiting up to 2 seconds
Press Ctrl-C to quit
This is the Query which query which is getting timed out:
ALTER TABLE "request_log_requestlog2" ADD COLUMN "request_type" smallint NULL CHECK ("request_type" >= 0)
my best guess is that “ALTER TABLE” command is trying to get a lock on the entire table
but since the table is being continuously written to, it’s not able to get the lock in time
Can someone help me with this?

"Unique constrainted failed" problem when running migrations

I have been tryed to change a django model by applying and running migrations but I have been getting this error django.db.utils.IntegrityError: UNIQUE constraint failed: new__startup_home_mates.user_id How can this error be fixed? I have already investigated a lot but I have found nothing that fits my situation. I have already tried to use RenameField and AlterField directly from the migrations file and it is still not working maybe I was doing it wrong.
models.py
class Mates(models.Model):
user = models.OneToOneField(User, on_delete=models.CASCADE, related_name='usermates', unique=True)
users_requests = models.ManyToManyField(User, related_name="users_requests")
req_bio = models.CharField(max_length=400)
req_image = models.ImageField(upload_to='requestmates_pics', null=True, blank=True, default=False)
traceback
Traceback (most recent call last):
File "manage.py", line 21, in <module>
main()
File "manage.py", line 17, in main
execute_from_command_line(sys.argv)
File "C:\Users\USER\Envs\startup\lib\site-packages\django\core\management\__init__.py", line 401, in execute_from_command_line
utility.execute()
File "C:\Users\USER\Envs\startup\lib\site-packages\django\core\management\__init__.py", line 395, in execute
self.fetch_command(subcommand).run_from_argv(self.argv)
File "C:\Users\USER\Envs\startup\lib\site-packages\django\core\management\base.py", line 328, in run_from_argv
self.execute(*args, **cmd_options)
File "C:\Users\USER\Envs\startup\lib\site-packages\django\core\management\base.py", line 369, in execute
output = self.handle(*args, **options)
File "C:\Users\USER\Envs\startup\lib\site-packages\django\core\management\base.py", line 83, in wrapped
res = handle_func(*args, **kwargs)
File "C:\Users\USER\Envs\startup\lib\site-packages\django\core\management\commands\migrate.py", line 231, in handle
post_migrate_state = executor.migrate(
File "C:\Users\USER\Envs\startup\lib\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 "C:\Users\USER\Envs\startup\lib\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 "C:\Users\USER\Envs\startup\lib\site-packages\django\db\migrations\executor.py", line 245, in apply_migration
state = migration.apply(state, schema_editor)
File "C:\Users\USER\Envs\startup\lib\site-packages\django\db\migrations\migration.py", line 124, in apply
operation.database_forwards(self.app_label, schema_editor, old_state, project_state)
File "C:\Users\USER\Envs\startup\lib\site-packages\django\db\migrations\operations\fields.py", line 249, in database_forwards
schema_editor.alter_field(from_model, from_field, to_field)
File "C:\Users\USER\Envs\startup\lib\site-packages\django\db\backends\sqlite3\schema.py", line 138, in alter_field
super().alter_field(model, old_field, new_field, strict=strict)
File "C:\Users\USER\Envs\startup\lib\site-packages\django\db\backends\base\schema.py", line 564, in alter_field
self._alter_field(model, old_field, new_field, old_type, new_type,
File "C:\Users\USER\Envs\startup\lib\site-packages\django\db\backends\sqlite3\schema.py", line 360, in _alter_field
self._remake_table(model, alter_field=(old_field, new_field))
File "C:\Users\USER\Envs\startup\lib\site-packages\django\db\backends\sqlite3\schema.py", line 283, in _remake_table
self.execute("INSERT INTO %s (%s) SELECT %s FROM %s" % (
File "C:\Users\USER\Envs\startup\lib\site-packages\django\db\backends\base\schema.py", line 142, in execute
cursor.execute(sql, params)
File "C:\Users\USER\Envs\startup\lib\site-packages\django\db\backends\utils.py", line 100, in execute
return super().execute(sql, params)
File "C:\Users\USER\Envs\startup\lib\site-packages\django\db\backends\utils.py", line 68, in execute
return self._execute_with_wrappers(sql, params, many=False, executor=self._execute)
File "C:\Users\USER\Envs\startup\lib\site-packages\django\db\backends\utils.py", line 77, in _execute_with_wrappers
return executor(sql, params, many, context)
File "C:\Users\USER\Envs\startup\lib\site-packages\django\db\backends\utils.py", line 86, in _execute
return self.cursor.execute(sql, params)
File "C:\Users\USER\Envs\startup\lib\site-packages\django\db\utils.py", line 90, in __exit__
raise dj_exc_value.with_traceback(traceback) from exc_value
File "C:\Users\USER\Envs\startup\lib\site-packages\django\db\backends\utils.py", line 86, in _execute
return self.cursor.execute(sql, params)
File "C:\Users\USER\Envs\startup\lib\site-packages\django\db\backends\sqlite3\base.py", line 396, in execute
return Database.Cursor.execute(self, query, params)
django.db.utils.IntegrityError: UNIQUE constraint failed: new__startup_home_mates.user_id
If you need to see more code please let me know:)

You may added a primary key / id with your models later, but previous database does not have it.
If you add new features to models, add default='something', or null=True,blank=True as arguments. So that old database won't need the unique constraints/value

I suspect that your problem is with your OnetoOneField with unique set to True. You should change this to a ForeignKey (and don't set Unique = True). This is so that users can have more than one mate. That is if I have correctly understood your model setup and what you are trying to achieve.
Here is a good summary of the differences between OnetoOneField and ForeignKey:
What's the difference between django OneToOneField and ForeignKey?

[Django]django.db.utils.IntegrityError

my app named mainsite
I have the table class named Weather in models.py
class Weather(models.Model):
tpr = models.CharField(max_length=5)
wet = models.CharField(max_length=5)
ur = models.CharField(max_length=5)
li = models.CharField(max_length=5)
observe_time = models.DateTimeField(default=None)
I don't want my observe_time set any deafult value
So I set to None .
I have made migrations.
when I made migrate
Then the traceback happen:
File "manage.py", line 22, in
execute_from_command_line(sys.argv)
File "C:\Users\User\Anaconda3\lib\site-packages\django\core\management__init__.py",
line 354, in execute_from_command_line
utility.execute() File "C:\Users\User\Anaconda3\lib\site-packages\django\core\management\__init__.py",
line 346, in execute
self.fetch_command(subcommand).run_from_argv(self.argv) File "C:\Users\User\Anaconda3\lib\site-packages\django\core\management\base.py",
line 394, in run_from_argv
self.execute(*args, **cmd_options) File "C:\Users\User\Anaconda3\lib\site-packages\django\core\management\base.py",
line 445, in execute
output = self.handle(*args, **options) File "C:\Users\User\Anaconda3\lib\site-packages\django\core\management\commands\migrate.py",
line 222, in handle
executor.migrate(targets, plan, fake=fake, fake_initial=fake_initial) File
"C:\Users\User\Anaconda3\lib\site-packages\django\db\migrations\executor.py",
line 110, in migrate
self.apply_migration(states[migration], migration, fake=fake, fake_initial=fake_initial) File
"C:\Users\User\Anaconda3\lib\site-packages\django\db\migrations\executor.py",
line 148, in apply_migration
state = migration.apply(state, schema_editor) File "C:\Users\User\Anaconda3\lib\site-packages\django\db\migrations\migration.py",
line 115, in apply
operation.database_forwards(self.app_label, schema_editor, old_state, project_state) File
"C:\Users\User\Anaconda3\lib\site-packages\django\db\migrations\operations\fields.py",
line 62, in database_forwards
field, File "C:\Users\User\Anaconda3\lib\site-packages\django\db\backends\sqlite3\schema.py",
line 179, in add_field
self._remake_table(model, create_fields=[field]) File "C:\Users\User\Anaconda3\lib\site-packages\django\db\backends\sqlite3\schema.py",
line 147, in _remake_table
self.quote_name(model._meta.db_table), File "C:\Users\User\Anaconda3\lib\site-packages\django\db\backends\base\schema.py",
line 111, in execute
cursor.execute(sql, params) File "C:\Users\User\Anaconda3\lib\site-packages\django\db\backends\utils.py",
line 79, in execute
return super(CursorDebugWrapper, self).execute(sql, params) File "C:\Users\User\Anaconda3\lib\site-packages\django\db\backends\utils.py",
line 64, in execute
return self.cursor.execute(sql, params) File "C:\Users\User\Anaconda3\lib\site-packages\django\db\utils.py", line
98, in exit
six.reraise(dj_exc_type, dj_exc_value, traceback) File "C:\Users\User\Anaconda3\lib\site-packages\django\utils\six.py", line
685, in reraise
raise value.with_traceback(tb) File "C:\Users\User\Anaconda3\lib\site-packages\django\db\backends\utils.py",
line 64, in execute
return self.cursor.execute(sql, params) File "C:\Users\User\Anaconda3\lib\site-packages\django\db\backends\sqlite3\base.py",
line 318, in execute
return Database.Cursor.execute(self, query, params) django.db.utils.IntegrityError: NOT NULL constraint failed:
mainsite_weather__new.observe_time
I don't know what caused this error.
thx.

In order for this to work you should also make this field nullable and blankable, like this:
observe_time = models.DateTimeField(default=None, blank=True, null=True)
or omit default=None completely, like this:
observe_time = models.DateTimeField(blank=True, null=True)
Also, after that, don't forget to delete the previous migration file and run makemigrations and migrate again.

django.db.utils.ProgrammingError: column am.amcanorder does not exist

I am using PostgreSQL as my database and using django tenant schemas. But when I run the following command python manage.py migrate_schemas --shared I get the error saying
(checkpoint_env)
G:\Django_Projects\RackNole\checkpoint_shashi_2\checkpoint_shashi_2>python manage.py migrate_schemas --shared
System check identified some issues:
WARNINGS:
checkpoint.MultiSelectResponse.response: (fields.W340) null has no effect on ManyToManyField.
=== Running migrate for schema public
System check identified some issues:
WARNINGS:
checkpoint.MultiSelectResponse.response: (fields.W340) null has no effect on ManyToManyField.
Operations to perform:
Apply all migrations: website, checkpoint, account, django_comments, redirects, core, admin, twitter, galleries, tastypie, customers, auth, sites, blog, generic, contenttypes, sessions, conf, forms, pages, socialaccount
Running migrations:
Rendering model states... DONE
Applying core.0002_auto_20150414_2140...Traceback (most recent call last):
File "manage.py", line 10, in <module>
execute_from_command_line(sys.argv)
File "G:\Py_Envs\Racknole\checkpoint_env\lib\site-packages\django\core\management\__init__.py", line 350, in execute_from_command_line
utility.execute()
File "G:\Py_Envs\Racknole\checkpoint_env\lib\site-packages\django\core\management\__init__.py", line 342, in execute
self.fetch_command(subcommand).run_from_argv(self.argv)
File "G:\Py_Envs\Racknole\checkpoint_env\lib\site-packages\django\core\management\base.py", line 348, in run_from_argv
self.execute(*args, **cmd_options)
File "G:\Py_Envs\Racknole\checkpoint_env\lib\site-packages\django\core\management\base.py", line 399, in execute
output = self.handle(*args, **options)
File "G:\Py_Envs\Racknole\checkpoint_env\lib\site-packages\tenant_schemas\management\commands\migrate_schemas.py", line 42, in handle
self.run_migrations(self.schema_name, settings.SHARED_APPS)
File "G:\Py_Envs\Racknole\checkpoint_env\lib\site-packages\tenant_schemas\management\commands\migrate_schemas.py", line 65, in run_migrations
command.execute(*self.args, **self.options)
File "G:\Py_Envs\Racknole\checkpoint_env\lib\site-packages\django\core\management\base.py", line 399, in execute
output = self.handle(*args, **options)
File "G:\Py_Envs\Racknole\checkpoint_env\lib\site-packages\django\core\management\commands\migrate.py", line 200, in handle
executor.migrate(targets, plan, fake=fake, fake_initial=fake_initial)
File "G:\Py_Envs\Racknole\checkpoint_env\lib\site-packages\django\db\migrations\executor.py", line 92, in migrate
self._migrate_all_forwards(plan, full_plan, fake=fake, fake_initial=fake_initial)
File "G:\Py_Envs\Racknole\checkpoint_env\lib\site-packages\django\db\migrations\executor.py", line 121, in _migrate_all_forwards
state = self.apply_migration(state, migration, fake=fake, fake_initial=fake_initial)
File "G:\Py_Envs\Racknole\checkpoint_env\lib\site-packages\django\db\migrations\executor.py", line 198, in apply_migration
state = migration.apply(state, schema_editor)
File "G:\Py_Envs\Racknole\checkpoint_env\lib\site-packages\django\db\migrations\migration.py", line 123, in apply
operation.database_forwards(self.app_label, schema_editor, old_state, project_state)
File "G:\Py_Envs\Racknole\checkpoint_env\lib\site-packages\django\db\migrations\operations\fields.py", line 201, in database_forwards
schema_editor.alter_field(from_model, from_field, to_field)
File "G:\Py_Envs\Racknole\checkpoint_env\lib\site-packages\django\db\backends\base\schema.py", line 482, in alter_field
old_db_params, new_db_params, strict)
File "G:\Py_Envs\Racknole\checkpoint_env\lib\site-packages\django\db\backends\base\schema.py", line 491, in _alter_field
fk_names = self._constraint_names(model, [old_field.column], foreign_key=True)
File "G:\Py_Envs\Racknole\checkpoint_env\lib\site-packages\django\db\backends\base\schema.py", line 911, in _constraint_names
constraints = self.connection.introspection.get_constraints(cursor, model._meta.db_table)
File "G:\Py_Envs\Racknole\checkpoint_env\lib\site-packages\tenant_schemas\postgresql_backend\introspection.py", line 287, in get_constraints
'table': table_name,
File "G:\Py_Envs\Racknole\checkpoint_env\lib\site-packages\django\db\backends\utils.py", line 79, in execute
return super(CursorDebugWrapper, self).execute(sql, params)
File "G:\Py_Envs\Racknole\checkpoint_env\lib\site-packages\django\db\backends\utils.py", line 64, in execute
return self.cursor.execute(sql, params)
File "G:\Py_Envs\Racknole\checkpoint_env\lib\site-packages\django\db\utils.py", line 95, in __exit__
six.reraise(dj_exc_type, dj_exc_value, traceback)
File "G:\Py_Envs\Racknole\checkpoint_env\lib\site-packages\django\db\backends\utils.py", line 64, in execute
return self.cursor.execute(sql, params)
django.db.utils.ProgrammingError: column am.amcanorder does not exist
LINE 13: WHEN am.amcanorder THEN

In PostgreSQL up to 9.5 amcanorder was pg_am catalog column. In PostgreSQL 9.6 it was removed. Apparently, django-tenant-schemas uses it.

django changing a date field to integer field can't migrate

I recently changed a date field to an integer field (the data was specified in number of months remaining rather than a date).
However all though the make migrations command works fine when I attempt to migrate this fails with a typecast error (note using postgres 9.5). Note there was only 1 instance/entry of the model, which I have also now deleted and the migrate still fails for some reason?
File "/Users/Yunti/.virtualenvs/switcher5/lib/python3.5/site-packages/django/db/backends/utils.py", line 64, in execute
return self.cursor.execute(sql, params)
psycopg2.ProgrammingError: cannot cast type date to integer
LINE 1: ...end_date_fixed" TYPE integer USING "end_date_fixed"::integer
^
The above exception was the direct cause of the following exception:
Traceback (most recent call last):
File "manage.py", line 10, in <module>
execute_from_command_line(sys.argv)
File "/Users/Yunti/.virtualenvs/switcher5/lib/python3.5/site-packages/django/core/management/__init__.py", line 353, in execute_from_command_line
utility.execute()
File "/Users/Yunti/.virtualenvs/switcher5/lib/python3.5/site-packages/django/core/management/__init__.py", line 345, in execute
self.fetch_command(subcommand).run_from_argv(self.argv)
File "/Users/Yunti/.virtualenvs/switcher5/lib/python3.5/site-packages/django/core/management/base.py", line 348, in run_from_argv
self.execute(*args, **cmd_options)
File "/Users/Yunti/.virtualenvs/switcher5/lib/python3.5/site-packages/django/core/management/base.py", line 399, in execute
output = self.handle(*args, **options)
File "/Users/Yunti/.virtualenvs/switcher5/lib/python3.5/site-packages/django/core/management/commands/migrate.py", line 200, in handle
executor.migrate(targets, plan, fake=fake, fake_initial=fake_initial)
File "/Users/Yunti/.virtualenvs/switcher5/lib/python3.5/site-packages/django/db/migrations/executor.py", line 92, in migrate
self._migrate_all_forwards(plan, full_plan, fake=fake, fake_initial=fake_initial)
File "/Users/Yunti/.virtualenvs/switcher5/lib/python3.5/site-packages/django/db/migrations/executor.py", line 121, in _migrate_all_forwards
state = self.apply_migration(state, migration, fake=fake, fake_initial=fake_initial)
File "/Users/Yunti/.virtualenvs/switcher5/lib/python3.5/site-packages/django/db/migrations/executor.py", line 198, in apply_migration
state = migration.apply(state, schema_editor)
File "/Users/Yunti/.virtualenvs/switcher5/lib/python3.5/site-packages/django/db/migrations/migration.py", line 123, in apply
operation.database_forwards(self.app_label, schema_editor, old_state, project_state)
File "/Users/Yunti/.virtualenvs/switcher5/lib/python3.5/site-packages/django/db/migrations/operations/fields.py", line 201, in database_forwards
schema_editor.alter_field(from_model, from_field, to_field)
File "/Users/Yunti/.virtualenvs/switcher5/lib/python3.5/site-packages/django/db/backends/base/schema.py", line 482, in alter_field
old_db_params, new_db_params, strict)
File "/Users/Yunti/.virtualenvs/switcher5/lib/python3.5/site-packages/django/db/backends/postgresql/schema.py", line 110, in _alter_field
new_db_params, strict,
File "/Users/Yunti/.virtualenvs/switcher5/lib/python3.5/site-packages/django/db/backends/base/schema.py", line 634, in _alter_field
params,
File "/Users/Yunti/.virtualenvs/switcher5/lib/python3.5/site-packages/django/db/backends/base/schema.py", line 110, in execute
cursor.execute(sql, params)
File "/Users/Yunti/.virtualenvs/switcher5/lib/python3.5/site-packages/django/db/backends/utils.py", line 79, in execute
return super(CursorDebugWrapper, self).execute(sql, params)
File "/Users/Yunti/.virtualenvs/switcher5/lib/python3.5/site-packages/django/db/backends/utils.py", line 64, in execute
return self.cursor.execute(sql, params)
File "/Users/Yunti/.virtualenvs/switcher5/lib/python3.5/site-packages/django/db/utils.py", line 95, in __exit__
six.reraise(dj_exc_type, dj_exc_value, traceback)
File "/Users/Yunti/.virtualenvs/switcher5/lib/python3.5/site-packages/django/utils/six.py", line 685, in reraise
raise value.with_traceback(tb)
File "/Users/Yunti/.virtualenvs/switcher5/lib/python3.5/site-packages/django/db/backends/utils.py", line 64, in execute
return self.cursor.execute(sql, params)
django.db.utils.ProgrammingError: cannot cast type date to integer
LINE 1: ...end_date_fixed" TYPE integer USING "end_date_fixed"::integer

If the table is empty.
Do the migration in two simple steps. Step 1, drop the existing date column from the model. Step 2 add a new INTEGER column with the same column name.
If the table is not empty.
Edit your model to change the type of end_date_fixed to integer as you have done. Do the make migrations, the open the migrations and delete everything inside migrations[] then replacce it with
migrations.RunSQL("ALTER TABLE mytable ALTER end_date_fixed TYPE INTEGER USING EXTRACT(epoch FROM end_date_fixed)
Make sure that you have not made any other changes to the model when you try this method.