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TypeError: expected string or bytes-like object - Django

I've deployed my Django application to DigitalOcean server via nginx, gunicorn. Today I wanted to add the script models.DateTimeField(auto_now_add=True) for saving the date when message from user was sent, but during migration (after pulling the entire repository from github on ubuntu server) I'm getting following error. And I guess the problem is in migration files, but don't know how can I manipulate them on server and how to do it safely, without losing any data.
Error:
Applying pragmatechapp.0004_auto_20200328_1036...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 "/home/kerimov/pragmatechproject/env/lib/python3.5/site-packages/django/core/management/__init__.py", line 381, in execute_from_command_line
utility.execute()
File "/home/kerimov/pragmatechproject/env/lib/python3.5/site-packages/django/core/management/__init__.py", line 375, in execute
self.fetch_command(subcommand).run_from_argv(self.argv)
File "/home/kerimov/pragmatechproject/env/lib/python3.5/site-packages/django/core/management/base.py", line 323, in run_from_argv
self.execute(*args, **cmd_options)
File "/home/kerimov/pragmatechproject/env/lib/python3.5/site-packages/django/core/management/base.py", line 364, in execute
output = self.handle(*args, **options)
File "/home/kerimov/pragmatechproject/env/lib/python3.5/site-packages/django/core/management/base.py", line 83, in wrapped
res = handle_func(*args, **kwargs)
File "/home/kerimov/pragmatechproject/env/lib/python3.5/site-packages/django/core/management/commands/migrate.py", line 234, in handle
fake_initial=fake_initial,
File "/home/kerimov/pragmatechproject/env/lib/python3.5/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/kerimov/pragmatechproject/env/lib/python3.5/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/kerimov/pragmatechproject/env/lib/python3.5/site-packages/django/db/migrations/executor.py", line 245, in apply_migration
state = migration.apply(state, schema_editor)
File "/home/kerimov/pragmatechproject/env/lib/python3.5/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/kerimov/pragmatechproject/env/lib/python3.5/site-packages/django/db/migrations/operations/fields.py", line 112, in database_forwards
field,
File "/home/kerimov/pragmatechproject/env/lib/python3.5/site-packages/django/db/backends/base/schema.py", line 433, in add_field
definition, params = self.column_sql(model, field, include_default=True)
File "/home/kerimov/pragmatechproject/env/lib/python3.5/site-packages/django/db/backends/base/schema.py", line 161, in column_sql
default_value = self.effective_default(field)
File "/home/kerimov/pragmatechproject/env/lib/python3.5/site-packages/django/db/backends/base/schema.py", line 233, in effective_default
return field.get_db_prep_save(self._effective_default(field), self.connection)
File "/home/kerimov/pragmatechproject/env/lib/python3.5/site-packages/django/db/models/fields/__init__.py", line 793, in get_db_prep_save
return self.get_db_prep_value(value, connection=connection, prepared=False)
File "/home/kerimov/pragmatechproject/env/lib/python3.5/site-packages/django/db/models/fields/__init__.py", line 1435, in get_db_prep_value
value = self.get_prep_value(value)
File "/home/kerimov/pragmatechproject/env/lib/python3.5/site-packages/django/db/models/fields/__init__.py", line 1414, in get_prep_value
value = super().get_prep_value(value)
File "/home/kerimov/pragmatechproject/env/lib/python3.5/site-packages/django/db/models/fields/__init__.py", line 1274, in get_prep_value
return self.to_python(value)
File "/home/kerimov/pragmatechproject/env/lib/python3.5/site-packages/django/db/models/fields/__init__.py", line 1375, in to_python
parsed = parse_datetime(value)
File "/home/kerimov/pragmatechproject/env/lib/python3.5/site-packages/django/utils/dateparse.py", line 106, in parse_datetime
match = datetime_re.match(value)
TypeError: expected string or bytes-like object
Note: I should solve this problem very quickly, please, everyone, who knows the answer, help me. I'm really depressed and stressed.

As a solution I've used deleting the migrations one by one with a command find . -path "*/migrations/{my_migration_names}.py" -not -name "__init__.py" -delete. To get name of all of my migration files you should run python3 manage.py showmigrations command.

Django manage.py migrate ValidationError

While running django when I use python manage.py migrate I am encountering the following error after running python manage.py makemigrations
File "manage.py", line 22, in <module>
execute_from_command_line(sys.argv)
File "/Users/rasikraj/Desktop/eb-virt/lib/python3.7/site-packages/django/core/management/__init__.py", line 381, in execute_from_command_line
utility.execute()
File "/Users/rasikraj/Desktop/eb-virt/lib/python3.7/site-packages/django/core/management/__init__.py", line 375, in execute
self.fetch_command(subcommand).run_from_argv(self.argv)
File "/Users/rasikraj/Desktop/eb-virt/lib/python3.7/site-packages/django/core/management/base.py", line 323, in run_from_argv
self.execute(*args, **cmd_options)
File "/Users/rasikraj/Desktop/eb-virt/lib/python3.7/site-packages/django/core/management/base.py", line 364, in execute
output = self.handle(*args, **options)
File "/Users/rasikraj/Desktop/eb-virt/lib/python3.7/site-packages/django/core/management/base.py", line 83, in wrapped
res = handle_func(*args, **kwargs)
File "/Users/rasikraj/Desktop/eb-virt/lib/python3.7/site-packages/django/core/management/commands/migrate.py", line 234, in handle
fake_initial=fake_initial,
File "/Users/rasikraj/Desktop/eb-virt/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 "/Users/rasikraj/Desktop/eb-virt/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 "/Users/rasikraj/Desktop/eb-virt/lib/python3.7/site-packages/django/db/migrations/executor.py", line 245, in apply_migration
state = migration.apply(state, schema_editor)
File "/Users/rasikraj/Desktop/eb-virt/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 "/Users/rasikraj/Desktop/eb-virt/lib/python3.7/site-packages/django/db/migrations/operations/fields.py", line 112, in database_forwards
field,
File "/Users/rasikraj/Desktop/eb-virt/lib/python3.7/site-packages/django/db/backends/base/schema.py", line 433, in add_field
definition, params = self.column_sql(model, field, include_default=True)
File "/Users/rasikraj/Desktop/eb-virt/lib/python3.7/site-packages/django/db/backends/base/schema.py", line 161, in column_sql
default_value = self.effective_default(field)
File "/Users/rasikraj/Desktop/eb-virt/lib/python3.7/site-packages/django/db/backends/base/schema.py", line 233, in effective_default
return field.get_db_prep_save(self._effective_default(field), self.connection)
File "/Users/rasikraj/Desktop/eb-virt/lib/python3.7/site-packages/django/db/models/fields/__init__.py", line 789, in get_db_prep_save
return self.get_db_prep_value(value, connection=connection, prepared=False)
File "/Users/rasikraj/Desktop/eb-virt/lib/python3.7/site-packages/django/db/models/fields/__init__.py", line 1429, in get_db_prep_value
value = self.get_prep_value(value)
File "/Users/rasikraj/Desktop/eb-virt/lib/python3.7/site-packages/django/db/models/fields/__init__.py", line 1408, in get_prep_value
value = super().get_prep_value(value)
File "/Users/rasikraj/Desktop/eb-virt/lib/python3.7/site-packages/django/db/models/fields/__init__.py", line 1268, in get_prep_value
return self.to_python(value)
File "/Users/rasikraj/Desktop/eb-virt/lib/python3.7/site-packages/django/db/models/fields/__init__.py", line 1393, in to_python
params={'value': value},
django.core.exceptions.ValidationError: ["'' value has an invalid format. It must be in YYYY-MM-DD HH:MM[:ss[.uuuuuu]][TZ] format."]
What could be the cause of this error and How can I ressolve this issue.
I'm using python 3.7 and Django 2.2

Based on the error, there is a DateTimeField [Django-doc] with as default='' [Django-doc]. But that is not a valid default: a DateTimeField should have store a datetime in the database (or None in case the field is NULL-able).
You thus should provide a valid default for that DateTimeField, for example:
from django.utils import timezone
class SomeModel(models.Model):
my_field = DateTimeField(default=timezone.now)
or you can omit the default value, and run makemigrations. In that case Django will ask if you want to provide a one-off default that will be applied to the records already in the database.
When you have changed the field you will need to remove the (invalid) migration file that was constructed where adding (or changing) that field took place, and make new migrations with manage.py makemigrations. After all, this validation does not occur when constructing the migration files, and now that you migrate it will indeed error. If you later change your model, the invalid migration fill is still not performed, hence it will raise the same error again.

Getting Migrate Error on Model Field that doesn't exist

Ran my server today and realized I had 'two unapplied migrations'. I ran the command makemigrations and it detected no change, so naturally I then ran migrate.
I get this error code on my terminal:
Applying Campaigns.0016_campaignrecruit_date...Traceback (most recent call last):
File "manage.py", line 15, in <module>
execute_from_command_line(sys.argv)
File "/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/site-packages/django/core/management/__init__.py", l
ine 371, in execute_from_command_line
utility.execute()
File "/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/site-packages/django/core/management/__init__.py", l
ine 365, in execute
self.fetch_command(subcommand).run_from_argv(self.argv)
File "/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/site-packages/django/core/management/base.py", line
288, in run_from_argv
self.execute(*args, **cmd_options)
File "/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/site-packages/django/core/management/base.py", line
335, in execute
output = self.handle(*args, **options)
File "/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/site-packages/django/core/management/commands/migrat
e.py", line 200, in handle
fake_initial=fake_initial,
File "/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/site-packages/django/db/migrations/executor.py", lin
e 117, in migrate
state = self._migrate_all_forwards(state, plan, full_plan, fake=fake, fake_initial=fake_initial)
File "/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/site-packages/django/db/migrations/executor.py", lin
e 147, in _migrate_all_forwards
state = self.apply_migration(state, migration, fake=fake, fake_initial=fake_initial)
File "/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/site-packages/django/db/migrations/executor.py", lin
e 244, in apply_migration
state = migration.apply(state, schema_editor)
File "/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/site-packages/django/db/migrations/migration.py", li
ne 122, in apply
operation.database_forwards(self.app_label, schema_editor, old_state, project_state)
File "/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/site-packages/django/db/migrations/operations/fields
.py", line 84, in database_forwards
field,
File "/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/site-packages/django/db/backends/sqlite3/schema.py",
line 306, in add_field
self._remake_table(model, create_field=field)
File "/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/site-packages/django/db/backends/sqlite3/schema.py",
line 178, in _remake_table
self.effective_default(create_field)
File "/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/site-packages/django/db/backends/base/schema.py", li
ne 240, in effective_default
default = field.get_db_prep_save(default, self.connection)
File "/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/site-packages/django/db/models/fields/__init__.py",
line 767, in get_db_prep_save
return self.get_db_prep_value(value, connection=connection, prepared=False)
File "/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/site-packages/django/db/models/fields/__init__.py",
line 1276, in get_db_prep_value
value = self.get_prep_value(value)
File "/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/site-packages/django/db/models/fields/__init__.py",
line 1271, in get_prep_value
return self.to_python(value)
File "/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/site-packages/django/db/models/fields/__init__.py",
line 1233, in to_python
parsed = parse_date(value)
File "/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/site-packages/django/utils/dateparse.py", line 74, i
n parse_date
match = date_re.match(value)
TypeError: expected string or bytes-like object
So to me, it looks like a date field in my model campaignrecruit is getting an input that it doesn't know how to handle. Which I would understand. But the thing is I don't have a datefield in my campaignrecruit model. The Time field is intentionally commented out right now.
Here's my models.py:
class campaignrecruit(models.Model):
campaign = models.ForeignKey(startcampaign, on_delete=models.CASCADE)
volunteer = models.ForeignKey(settings.AUTH_USER_MODEL, on_delete=models.CASCADE)
join = models.BooleanField()
#Time = models.IntegerField()
def __str__(self):
return str(self.volunteer)
What else would throw this error? Any and all help is appreciated.

Since no one else answered, I will. As Aritra stated, I totally forgot about the migration files that are created whenever you run the migrate command. I had removed these model fields from my models and whenever I migrated again there was an error removing the files in my migrations file. After manually going in and removing the files, my error was fixed.
The database was just out of sync with what django had in its files.

Django migrations mixed up with 'PROTECT' and 'CASCADE'

I am stuck with migrations in django. I have two really basic models that will not migrate:
from django.db import models
# Create your models here.
class Instanz(models.Model):
type = models.CharField(max_length=30)
angelegt_am = models.DateField(auto_now_add=True)
class Person(models.Model):
instanz_fk = models.ForeignKey('Instanz', on_delete=models.CASCADE)
last_name = models.CharField(max_length=30)
first_name = models.CharField(max_length=30)
geburtsdatum = models.DateField()
It will raise the following exception. I dont get why it will search for a field named PROTECT. I used models.PROTECT in earlier migrations, before switching to CASCADE, but not any longer...
Operations to perform:
Apply all migrations: admin, auth, contenttypes, kundencenter, sessions
Running migrations:
Applying kundencenter.0001_initial...Traceback (most recent call last):
File "C:\Users\Micha\Dropbox\PycharmProjects\vertriebstool_virtualenv\lib\site-packages\django\db\models\options.py", line 617, in get_field
return self.fields_map[field_name]
KeyError: 'PROTECT'
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
File "C:\Users\Micha\Dropbox\PycharmProjects\vertriebstool\manage.py", line 22, in <module>
execute_from_command_line(sys.argv)
File "C:\Users\Micha\Dropbox\PycharmProjects\vertriebstool_virtualenv\lib\site-packages\django\core\management\__init__.py", line 367, in execute_from_command_line
utility.execute()
File "C:\Users\Micha\Dropbox\PycharmProjects\vertriebstool_virtualenv\lib\site-packages\django\core\management\__init__.py", line 359, in execute
self.fetch_command(subcommand).run_from_argv(self.argv)
File "C:\Users\Micha\Dropbox\PycharmProjects\vertriebstool_virtualenv\lib\site-packages\django\core\management\base.py", line 294, in run_from_argv
self.execute(*args, **cmd_options)
File "C:\Users\Micha\Dropbox\PycharmProjects\vertriebstool_virtualenv\lib\site-packages\django\core\management\base.py", line 345, in execute
output = self.handle(*args, **options)
File "C:\Users\Micha\Dropbox\PycharmProjects\vertriebstool_virtualenv\lib\site-packages\django\core\management\commands\migrate.py", line 204, in handle
fake_initial=fake_initial,
File "C:\Users\Micha\Dropbox\PycharmProjects\vertriebstool_virtualenv\lib\site-packages\django\db\migrations\executor.py", line 115, in migrate
state = self._migrate_all_forwards(state, plan, full_plan, fake=fake, fake_initial=fake_initial)
File "C:\Users\Micha\Dropbox\PycharmProjects\vertriebstool_virtualenv\lib\site-packages\django\db\migrations\executor.py", line 145, in _migrate_all_forwards
state = self.apply_migration(state, migration, fake=fake, fake_initial=fake_initial)
File "C:\Users\Micha\Dropbox\PycharmProjects\vertriebstool_virtualenv\lib\site-packages\django\db\migrations\executor.py", line 244, in apply_migration
state = migration.apply(state, schema_editor)
File "C:\Users\Micha\Dropbox\PycharmProjects\vertriebstool_virtualenv\lib\site-packages\django\db\migrations\migration.py", line 129, in apply
operation.database_forwards(self.app_label, schema_editor, old_state, project_state)
File "C:\Users\Micha\Dropbox\PycharmProjects\vertriebstool_virtualenv\lib\site-packages\django\db\migrations\operations\models.py", line 96, in database_forwards
schema_editor.create_model(model)
File "C:\Users\Micha\Dropbox\PycharmProjects\vertriebstool_virtualenv\lib\site-packages\django\db\backends\base\schema.py", line 246, in create_model
definition, extra_params = self.column_sql(model, field)
File "C:\Users\Micha\Dropbox\PycharmProjects\vertriebstool_virtualenv\lib\site-packages\django\db\backends\base\schema.py", line 136, in column_sql
db_params = field.db_parameters(connection=self.connection)
File "C:\Users\Micha\Dropbox\PycharmProjects\vertriebstool_virtualenv\lib\site-packages\django\db\models\fields\related.py", line 940, in db_parameters
return {"type": self.db_type(connection), "check": self.db_check(connection)}
File "C:\Users\Micha\Dropbox\PycharmProjects\vertriebstool_virtualenv\lib\site-packages\django\db\models\fields\related.py", line 937, in db_type
return self.target_field.rel_db_type(connection=connection)
File "C:\Users\Micha\Dropbox\PycharmProjects\vertriebstool_virtualenv\lib\site-packages\django\db\models\fields\related.py", line 855, in target_field
return self.foreign_related_fields[0]
File "C:\Users\Micha\Dropbox\PycharmProjects\vertriebstool_virtualenv\lib\site-packages\django\db\models\fields\related.py", line 595, in foreign_related_fields
return tuple(rhs_field for lhs_field, rhs_field in self.related_fields if rhs_field)
File "C:\Users\Micha\Dropbox\PycharmProjects\vertriebstool_virtualenv\lib\site-packages\django\db\models\fields\related.py", line 582, in related_fields
self._related_fields = self.resolve_related_fields()
File "C:\Users\Micha\Dropbox\PycharmProjects\vertriebstool_virtualenv\lib\site-packages\django\db\models\fields\related.py", line 575, in resolve_related_fields
else self.remote_field.model._meta.get_field(to_field_name))
File "C:\Users\Micha\Dropbox\PycharmProjects\vertriebstool_virtualenv\lib\site-packages\django\db\models\options.py", line 619, in get_field
raise FieldDoesNotExist('%s has no field named %r' % (self.object_name, field_name))
django.core.exceptions.FieldDoesNotExist: Instanz has no field named 'PROTECT'

Here's the deal: I messed up some earlier migrations that were blocking the process, because Djangos migrate uses all unaplied migrations.
I had to go to the folder \\migrations and delete all files (except init.py of course).
Everything works like a charm now.
If this happens in production, you would probably delete only the migrations to the point of the last working migration...

Django: change a model and migrate?

I've added an IntegerField to a Django model, but I just can't migrate it.
I type:
python3 migrate my_app
and it tells me that there are no migrations to apply. Then, of course, my admin page outputs an error because it can't find the new column! Any ideas?
Thanks
Edit: console output
Rendering model states... DONE
Applying jokes.0003_joke_no...Traceback (most recent call last):
File "manage.py", line 10, in <module>
execute_from_command_line(sys.argv)
File "/usr/local/lib/python3.4/dist-packages/django/core/management/__init__.py", line 338, in execute_from_command_line
utility.execute()
File "/usr/local/lib/python3.4/dist-packages/django/core/management/__init__.py", line 330, in execute
self.fetch_command(subcommand).run_from_argv(self.argv)
File "/usr/local/lib/python3.4/dist-packages/django/core/management/base.py", line 390, in run_from_argv
self.execute(*args, **cmd_options)
File "/usr/local/lib/python3.4/dist-packages/django/core/management/base.py", line 441, in execute
output = self.handle(*args, **options)
File "/usr/local/lib/python3.4/dist-packages/django/core/management/commands/migrate.py", line 221, in handle
executor.migrate(targets, plan, fake=fake, fake_initial=fake_initial)
File "/usr/local/lib/python3.4/dist-packages/django/db/migrations/executor.py", line 110, in migrate
self.apply_migration(states[migration], migration, fake=fake, fake_initial=fake_initial)
File "/usr/local/lib/python3.4/dist-packages/django/db/migrations/executor.py", line 147, in apply_migration
state = migration.apply(state, schema_editor)
File "/usr/local/lib/python3.4/dist-packages/django/db/migrations/migration.py", line 115, in apply
operation.database_forwards(self.app_label, schema_editor, old_state, project_state)
File "/usr/local/lib/python3.4/dist-packages/django/db/migrations/operations/fields.py", line 62, in database_forwards
field,
File "/usr/local/lib/python3.4/dist-packages/django/db/backends/sqlite3/schema.py", line 179, in add_field
self._remake_table(model, create_fields=[field])
File "/usr/local/lib/python3.4/dist-packages/django/db/backends/sqlite3/schema.py", line 77, in _remake_table
self.effective_default(field)
File "/usr/local/lib/python3.4/dist-packages/django/db/backends/base/schema.py", line 211, in effective_default
default = field.get_db_prep_save(default, self.connection)
File "/usr/local/lib/python3.4/dist-packages/django/db/models/fields/__init__.py", line 710, in get_db_prep_save
prepared=False)
File "/usr/local/lib/python3.4/dist-packages/django/db/models/fields/__init__.py", line 702, in get_db_prep_value
value = self.get_prep_value(value)
File "/usr/local/lib/python3.4/dist-packages/django/db/models/fields/__init__.py", line 1868, in get_prep_value
return int(value)
ValueError: invalid literal for int() with base 10: ''