Agfdhyk

I using Django version 2.0.7 and I tried to make a Date Module Field Until I faced this error :

Date = models.DateField(blank=True, default='', null=True, help_text='today date.')

I used this code before and it worked but now after python manage.py makemigrations that I use python manage.py migrate I faced to this error.
full logs:

Operations to perform:

  Apply all migrations: Blog, Portfolio, admin, auth, contenttypes, sessions

Running migrations:

  Applying Blog.0002_auto_20180728_0218...Traceback (most recent call last):

  File "manage.py", line 15, in <module>

    execute_from_command_line(sys.argv)

  File "D:LearnProjectsDjangomyvenvlibsite-packagesdjangocoremanagement__init__.py", line 371, in execute_from_command_line

    utility.execute()

  File "D:LearnProjectsDjangomyvenvlibsite-packagesdjangocoremanagement__init__.py", line 365, in execute

    self.fetch_command(subcommand).run_from_argv(self.argv)

  File "D:LearnProjectsDjangomyvenvlibsite-packagesdjangocoremanagementbase.py", line 288, in run_from_argv

    self.execute(*args, **cmd_options)

  File "D:LearnProjectsDjangomyvenvlibsite-packagesdjangocoremanagementbase.py", line 335, in execute

    output = self.handle(*args, **options)

  File "D:LearnProjectsDjangomyvenvlibsite-packagesdjangocoremanagementcommandsmigrate.py", line 200, in handle

    fake_initial=fake_initial,

  File "D:LearnProjectsDjangomyvenvlibsite-packagesdjangodbmigrationsexecutor.py", line 117, in migrate

    state = self._migrate_all_forwards(state, plan, full_plan, fake=fake, fake_initial=fake_initial)

  File "D:LearnProjectsDjangomyvenvlibsite-packagesdjangodbmigrationsexecutor.py", line 147, in _migrate_all_forwards

    state = self.apply_migration(state, migration, fake=fake, fake_initial=fake_initial)

  File "D:LearnProjectsDjangomyvenvlibsite-packagesdjangodbmigrationsexecutor.py", line 244, in apply_migration

    state = migration.apply(state, schema_editor)

  File "D:LearnProjectsDjangomyvenvlibsite-packagesdjangodbmigrationsmigration.py", line 122, in apply

    operation.database_forwards(self.app_label, schema_editor, old_state, project_state)

  File "D:LearnProjectsDjangomyvenvlibsite-packagesdjangodbmigrationsoperationsfields.py", line 216, in database_forwards

    schema_editor.alter_field(from_model, from_field, to_field)

  File "D:LearnProjectsDjangomyvenvlibsite-packagesdjangodbbackendsbaseschema.py", line 525, in alter_field

    old_db_params, new_db_params, strict)

  File "D:LearnProjectsDjangomyvenvlibsite-packagesdjangodbbackendspostgresqlschema.py", line 122, in _alter_field

    new_db_params, strict,

  File "D:LearnProjectsDjangomyvenvlibsite-packagesdjangodbbackendsbaseschema.py", line 629, in _alter_field

    old_default = self.effective_default(old_field)

  File "D:LearnProjectsDjangomyvenvlibsite-packagesdjangodbbackendsbaseschema.py", line 240, in effective_default

    default = field.get_db_prep_save(default, self.connection)

  File "D:LearnProjectsDjangomyvenvlibsite-packagesdjangodbmodelsfields__init__.py", line 767, in get_db_prep_save

    return self.get_db_prep_value(value, connection=connection, prepared=False)

  File "D:LearnProjectsDjangomyvenvlibsite-packagesdjangodbmodelsfields__init__.py", line 1276, in get_db_prep_value

    value = self.get_prep_value(value)

  File "D:LearnProjectsDjangomyvenvlibsite-packagesdjangodbmodelsfields__init__.py", line 1271, in get_prep_value

    return self.to_python(value)

  File "D:LearnProjectsDjangomyvenvlibsite-packagesdjangodbmodelsfields__init__.py", line 1246, in to_python

    params={'value': value},

django.core.exceptions.ValidationError: ["'' value has an invalid date format. It must be in YYYY-MM-DD format."]

I even try to remove all migrations and db and make new migrationsbut it doesn't work too.
this link doesnt work for me too :
Resolving ValidationError: [u“'' value has an invalid date format. It must be in YYYY-MM-DD format.”] in Django 1.9.2?

In Addision, I'm sorry for writing mistakes in my question.

The default can not be the empty string, since that is not a Date.
for example use date(1111, 11, 11) with from datetime import date in modals page
then if you will be get same error , you have to delete all migrations and erase your database data too and do migrations again.

import datetime



import pytz

from django.apps import AppConfig

from django.db.models.fields import DateTimeField

from django.utils.dateparse import parse_date

from django.core.exceptions import ValidationError



default_app_config = 'patch.PatchConfig'





def patch():

    def get_db_prep_value(self, value, connection, prepared=False):

        if isinstance(value, str):

            if not value:

                value = None

            elif not parse_date(value):

                try:

                    value = datetime.datetime.fromtimestamp(int(value)).replace(tzinfo=pytz.UTC)

                except:

                    raise ValidationError(

                        self.error_messages['invalid'],

                        code='invalid',

                        params={'value': value},

                    )

        if not prepared:

            value = self.get_prep_value(value)

        return connection.ops.adapt_datetimefield_value(value)



    DateTimeField.get_db_prep_value = get_db_prep_value





class PatchConfig(AppConfig):

    name = 'patch'



    def ready(self):

        patch()

You may be need this patch