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Relation does not exist error in Django after postgresql integration

I used sqlite3 during development, then changed my database settings to postgresql:
DATABASES = {
'default': {
'ENGINE': 'django.db.backends.postgresql_psycopg2',
'NAME': 'test2',
'USER': 'postgres',
'PASSWORD': 'aman',
'HOST': 'localhost',
'PORT': '5432',
}
}
Regardless of any command I write, it gives me the error:
django.db.utils.ProgrammingError: relation "taksist_category" does not exist
LINE 1: ...st_category"."id", "taksist_category"."name" FROM "taksist_c...
Category model exists inside taksist application. If I take back my database settings to sqlite3, then application runs successfully.
I cannot even run my server. Even if there is a problem with my model taksist/Category, my application should run. Here strange thing is whatever command is written, I got this error. I cannot do makemigrations, migrate, runserver.
What did I do to solve the issue:
deleted migrations folder, and tried makemigrations
I created empty migrations folder with init.py inside, and
tried makemigrations
python manage.py migrate --fake
none of above worked.
Here is taksist.category model, in case.
class Category(models.Model):
id = models.AutoField(primary_key=True)
name = models.CharField(max_length = 20)
def __str__(self):
return self.name
Any help of yours is appreciated. thank you in advance.

The root cause for "relation does not exist" is that migrations have not been run.
However, via the comments:
whatever command I execute, I got this error. even runserver, makemigrations and migrate. after change database settings to postgresql, i could not migrate. i can do nothing.
That is likely to mean you've written your application in a way that it accesses the database during initialization time, e.g. something like
from my_app.models import Blog
default_blog = Blog.objects.get(pk=1)
def view(...):
This means Django will attempt to access the database as soon as that module is imported. If that module gets imported while Django is trying to initialize itself for migrate, you get an exception.
You can look at the traceback for your django.db.utils.ProgrammingError to figure out what the offending access is and fix it. For instance, the above pattern would be better served by something like a get_default_blog() function.
If I take back my database settings to sqlite3, then application runs successfully.
This bug also means that if you rename or delete your current, working SQLite database, you can't get a new one going either, since attempting to migrate it would fail with a similar error. This is not just Postgres's "fault" here.

If it' a test DB do a py manage.py flush
command, then run the py manage.py makemigrations again, then the py manage.py migrate command.
That should resolve.

Django 1.8: Delete/rename a model field in data migration

I need to change the relationship of a model field from ForeignKey to ManyToManyField. This comes with a data migration, to update the pre-existing data.
The following is the original model (models.py):
class DealBase(models.Model):
[...]
categoria = models.ForeignKey('Categoria')
[...]
)
I need the model field 'categoria' to establish a many2many relationship with the model 'Categoria' in the app 'deal'.
What I did:
Create a new field 'categoria_tmp' in DealBase
class DealBase(models.Model):
categoria = models.ForeignKey('Categoria')
categoria_tmp = models.ManyToManyField('Categoria',related_name='categoria-temp')
make a schema migration
python manage.py makemigrations
Edit the migrationfile.py to migrate data from categoria to categoria-tmp
def copy_deal_to_dealtmp(apps, schema_editor):
DealBase = apps.get_model('deal', 'DealBase')
for deal in DealBase.objects.all():
deal.categoria_tmp.add(deal.categoria)
deal.save()
class Migration(migrations.Migration):
dependencies = [
('deal', '0017_dealbase_indirizzo'),
]
operations = [
migrations.AddField(
model_name='dealbase',
name='categoria_tmp',
field=models.ManyToManyField(related_name='categoria-temp', to='deal.Categoria'),
preserve_default=True,
),
migrations.RunPython(
copy_deal_to_dealtmp
)
]
make data migration
python manage.py migrate
Finally I need to delete the column 'dealbase.categoria' and rename the column 'dealbase.categoria-tmp' to 'dealbase.categoria'
I'm stuck at step 5.
Could someone help me out? I cannot find online an answer, I'm using Django 1.8.
Thanks!

You just need to create two additional migrations: one to remove the old field and the other to alter the new field.
First remove dealbase.categoria and create a migration and then rename dealbase.categoria-tmp to dealbase.categoria and create another migration.
This will delete the first field and then alter the tmp field to the correct name.

Try this, may help you.
Step 1 as yours
python manage.py makemigrations && python manage.py migrate
Open shell
for i in DealBase.objects.all()
i.categoria_tmp.add(i.categoria)
Remove your field categoria
python manage.py makemigrations && python manage.py migrate
Add field
categoria = models.ManyToManyField('Categoria',related_name='categoria-temp')
Then
python manage.py makemigrations && python manage.py migrate
Open shell
for i in DealBase.objects.all():
for j in i.categoria_tmp.all():
i.categoria.add(j)
Remove field categoria_tmp
python manage.py makemigrations && python manage.py migrate

If you don't have any data in this model, just comment on that model, and then run manage.py makemigrations and migrate. Then delete the wrong field and delete the comment code, and make makemigrations and migrate. This also works in Django 2.

Model Changes Django, Mezzanine, South

My model was
class Author(Page):
dob = models.DateField("Date of birth")
i removed dob field and updated model with:
class Author(Page):
name = models.CharField(max_length = 250)
email = models.EmailField()
Then entered two commands:
python manage.py schemamigration project_name 001_initial--add-field Author.name, Author.email
then this command
python manage.py migrate project_name
you can see attach image : these above commands don't allow me to save changes in models.
Need your assistance!

SOLUTION:
1)Before adding your new field go to command prompt and move to directory where your project or application is . Now write this command before adding fields in models.py file python manage.py schemamigration your_project_or_app_name --initial
2)Now write this command python manage.py migrate your_project_or_app_name --fake 0001 (or whichever migration number it returned - 0001 is you migration number) to set the south database to that state (tables already created).
3)Now go to your models.py file an add your new fields in your models.py file, then in your cmd run this command python manage schemamigration your_project_or_app_name --auto
4)Last step to save changes run this last migrate command python manage.py migrate your_project_or_app_name
Solution Reference :Django & South: Adding new field but DatabaseError occurs "table already exists" by Yuji 'Tomita' Tomita

Django, South, and Guardian: Migrate

I have two users, mh00h1 and mh00h2. I also have modelA that defines the following in my models.py:
class Meta:
permissions = (
('read','read'),
('write','write'),
)
From a shell, I went to set permissions:
>>>> frhde = create modelA instance
>>>> assign_perm('read', mh00h2, frhde)
DoesNotExist: Permission matching query does not exist. Lookup parameters were {'codename': u'read', 'content_type': <ContentType: modelA>}
I realized that South didn't migrate my models after I added class Meta to modelA and confirmed this. Changing read to read2 shows that South does not detect the change.
$ /manage.py schemamigration myapp --auto
Running migrations for myapp:
- Nothing to migrate.
- Loading initial data for myapp.
Installed 0 object(s) from 0 fixture(s)
Running migrations for guardian:
- Nothing to migrate.
- Loading initial data for guardian.
Installed 0 object(s) from 0 fixture(s)
How can I get schematicmigration to correctly update the database, or is there a better way to do this that does not require redoing the whole database?
Thank you.

You can use ./manage.py syncdb --all, or create a signal like in this post.

django south is changing my boolean data on init

To output my database to json file I would usually do
python manage.py dumptdata --indent=4 > mydata.json
However upon executing the following two commands to setup south:
python manage.py schemamigration myproj --initial
python manage.py migrate myproj --fake
I noticed that two of my booleans in mytable for an entry were switched from FALSE to TRUE! I see that from my GUI Web Interface interacting with the database however to more closely compare what changed and got corrupted I'd like to compare json to json but with south enabled I can no longer use the above command as it tells me
Not synced (use migrations):
- myproj
My table that had entries affected is below, I could have more affected data that I have not uncovered.
class MyConfig(models.Model):
name = models.CharField(max_length=64)
myConfigName = models.CharField(max_length=64, unique=True)
myA = models.ForeignKey(MyA)
myB = models.ForeignKey(MyB)
myBoolA = models.BooleanField()
myBoolB = models.BooleanField()
myBoolC = models.BooleanField()
class Meta:
unique_together = ('name', 'myA', 'myB')
def __unicode__(self):
return '%s_%s_%s' % (self.myA.name, self.myB.name, self.name)

schemamigration and migrate --fake don't modify the database. Do you have any initial_data fixture that could be reloaded when migrating? See https://docs.djangoproject.com/en/1.3/howto/initial-data/
Try to migrate with:
python manage.py migrate --no-initial-data
see south doc for more info about options

I don't think that either an --initial or a --fake should alter the database at all, so I'm surprised that it would modify data. In terms of why you're getting the "Not synced (use migrations)" error, I think it's likely because you faked the initial migration.
Try un-migrating the --fake and re-applying the initial migration with
python manage.py migrate --fake zero
python manage.py migrate
Then, you should be able to do the dumptdata