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Why does Django not see migrations?

I am trying to change some field names of Django models, but for some reasons Django does not want to see my migrations. I made sure the following things are properly set up:
myApp.apps.MyAppConfig is added to INSTALLED_APPS in settings.py
A migration folder with an empty __init__.py is present in my app folder
In myApp folder, I also have an empty __init__.py
The whole procedure works just fine locally with a SQLite database and I can change field names and run python manage.py makemigrations and python manage.py migrate to migrate the database. However in production where I use Docker Compose for orchestration and Postgres as database only the first migration works fine. Afterwards when I change any model field name and try to run docker-compose exec projectname django-admin makemigrations or docker-compose exec projectname python manage.py makemigrations or add the app name behind these commands nothing helps.
Then Postgres can't handle the request, because it doesn't know the new field name:
2022-03-11 14:40:22.136 UTC [81] ERROR: column model_name.new_field_name does not exist at character 357
What am I missing here? How can I get Django to migrate?

I had the same issues when using version control to submit changes to another environment.
What probably happens is that django believes it already made the migration, because of the information that is being passed along when you push those changes. What you need to do is to correct that behavior manually deleting those migrations or, if you don't need to keep information yet, force the migration from the beginning.
You may want to read the docs for future use, and I used the answers in this questions to solve the same issue.

At the end I was able to solve this issue by adding a Docker volume for the migrations folder. I believe a lot of times people put their entire code in a persistent volume, which would've also prevented this issue. However at least everything that needs to be persistent (obviously) needs a persistent volume.

I want to Create my first URL using the command prompt

I have Django installed,but I was trying to create my first URL and I typed the following using the command prompt
"cd myproject" then again I typed "manage.py runserver 127.0.0.1:8000" And I got the following output:
"System check identified no issues<0 silenced>
you have 17 unapplied migration. Your project may not work properly until you apply the migrations for app: admin,auth,contenttypes,sessions."
Please what do I do to fix this problem so that my project can work properly?
Note that: I am new in using Python and Django

You already have an advice to read the tutorial but in case you want to continue on your own (before next trouble), you need to run this in console in order to apply migrations:
python manage.py migrate
Read more about migrations and this command here.

You need to migrate the database first. But it's not error actually. It's just a warning. If you don't want to migrate(create DB tables) just ignore it. And you can still browse 127.0.0.1:8000
Migration command
python manage.py migrate
Read Django documentation very carefully. Django Official Documentation

Automated answer in django's makemigrations

I want to automate the python manage.py makemigrations as in if a user encounters Did you rename game.last to game.las (a CharField)? [y/N] then the input will always be y but if the user encounters You are trying to add a non-nullable field 'las' to game without a default then it will automatically and continuously enter 1.
I tried yes | python manage.py makemigrations as researched however this will just throw an infinite loop of Please select a valid option if the default input is asked
My desire is the automation between 1 and y value as mentioned on my first paragraph or just throw an error if I input a wrong option on the default input

First, run manage.py makemigrations locally. It makes a script to modify the database schema and that is part of development and places it in the project/migrations directory. Build the container such that the generated migrations are included in your Docker container (they should be automatically as they are part of the Django project source tree), and run manage.py migrate --noinput on start-up of the container. It will automatically apply any migrations that haven't been applied. Your migrations build up over time but you can squash them if you REALLY need to, I would recommend against it except rare circumstances.
This way, you will keep your development and production database schema in sync, and won't run into strange bugs because you generated new migrations on production that didn't exist in your development environment.
I would recommend purposefully designing your migrations so that they don't require any input on manage.py migrate. That is not always possible, for instance, stale models will sometimes require input and just be left there unless manually deleted.
Since all of the Django source is available to you, it's trivial to make a version of the migrate command that assumes y and place it as a management command. Then run that management command instead of migrate, done.
I would show an example of this but it is specific to the version of Django you are running.

I actually solved the problem via timeouts like timeout 30 yes | python manage.py makemigrations so if in case an infinite loop via wrong option selection on non-nullable field input returns. It will automatically exit after 30 seconds. Giving me an alternative somehow to proceed my CI/CD without pushing my migrations

Django Heroku and postgresql

I am new to publishing django apps on heroku.
I have read their tutorials and figured I would start simple by modifying their template django project.
So far everything was good.
Then I made an app as one does, made a model and ran
python3 manage.py makemigrations my_app
python3 manage.py migrate
and things seemed ok.
I then pushed to heroku and there were no immediate complaints.
However, now when I try to make save a new model I get the error:
ProgrammingError at /my_app/
relation "my_app_myappmodel" does not exist
LINE 1: INSERT INTO "my_app_myappmodel" ("field1", "field2", "field3") VALUES...
odd...
So I run this locally and everything works fine.
I have tried cleaning my migrations, faking my migrations, squashing my migrations, etc (as other S.O. posts suggest)
Nothing works.
What is up and how do I fix it?

You need to actually run the migrations on Heroku once you have pushed the code generated by makemigrations. You do this via heroku run manage.py migrate.

run the following command from your terminal
heroku run python manage.py migrate
or you can also do:
in your local settings.py, change your DATABASES variable to use the heroku one then run from the terminal
python manage.py makemigrations
python manage.py migrate
but you should not normally locally make changes to the heroku production database (as in option 2) except if you are really desperate or don't care

update django database to reflect changes in existing models

I've already defined a model and created its associated database via manager.py syncdb. Now that I've added some fields to the model, I tried syncdb again, but no output appears. Upon trying to access these new fields from my templates, I get a "No Such Column" exception, leading me to believe that syncdb didn't actually update the database. What's the right command here?

As of Django 1.7+, built-in migrations support, allows for database schema migrations that preserve data. That's probably a better approach than the solution below.
Another option, not requiring additional apps, is to use the built in manage.py functions to export your data, clear the database and restore the exported data.
The methods below will update the database tables for your app, but will completely destroy any data that existed in those tables. If the changes you made to your app model do not break your old schema (for instance, you added a new, optional field) you can simply dump the data before and reload it afterwards, like so:
Django 1.4.15 and earlier
python manage.py dumpdata <your_app> > temp_data.json
python manage.py reset <your_app>
python manage.py loaddata temp_data.json
Django 1.5 and newer
python manage.py dumpdata <your_app> > temp_data.json
python manage.py sqlclear <your_app> | python manage.py dbshell
python manage.py syncdb
python manage.py loaddata temp_data.json
(The reset command was deprecated and then removed in Django 1.5)
If your changes break your old schema this won't work - in which case tools like South or Django Evolution are great.

As of Django 1.7, you can now do this with native migrations. Just run
python manage.py makemigrations <your app name>
python manage.py migrate

Seems like what you need is a migration system. South is really nice, working great, has some automation tools to ease your workflow. And has a great tutorial.
note: syncdb can't update your existing tables. Sometimes it's impossible to decide what to do automagicly - that's why south scripts are this great.

Django's syncdb doesn't alter existing tables in the database so you have to do it manually. The way I always do it is:
Change the model class first.
Then run: manage.py sql myapp.
Look at the sql it prints out and see how it represented the change you are going to make.
Make the change manually using your database manager.
Check to see if everything worked correctly using the admin site.
If you are using sqllite a good manager is the firefox plugin: link

Another tool would be django evolution. No table dropping needed in most cases.
django evolution
Just install it as any other django app and run:
python manage.py evolve --hint --execute

deseb is a great tool for that.
Having it installed, you can write ./manage.py sqlevolve and it'll generate sql commands necessary to keep the database structure in sync with your models.

You need to drop your tables before you can recreate them with syncdb.
If you want to preserve your existing data, then you need to unload your database,
drop your tables, run syncdb to build a new database, then reload your old data into your new tables.
There are tools that help with this. However, in many cases, it's just as easy to do it manually.

For versions 1.4.1 and above users the command has changed to
python manage.py flush
Please read the official document before using it as it will delete all your data.