I have a Django website served by Heroku with a model storing data about projects that I've worked on in the past. I already ran makemigrations and migrate locally before pushing to heroku with git and running heroku run python3 manage.py migrate. So, my database models and fields are synced, but I'm asking about the field values. Whenever I update the value of a field for a model instance locally, I want it (the data) to sync with Heroku, and vice versa–sync values I've updated on Heroku in the admin panel with my local sqlite3 database. Is there a command for updating the values of the database itself, or am I missing something? Because I've looked all over the internet for the last hour for how to do this one thing and I couldn't find the command to do it.
Side note: I also want the command I'm looking for to sync newly created instances, not just data for existing model instances.
Ok, I've figured it out.
First step is to run python3 manage.py dumpdata --exclude contenttypes > data.json. This copies the local database data into a file called data.json (that's created by > also if it doesn't exist).
Next, git push to heroku and run heroku run python3 manage.py migrate for good measure.
Finally, heroku run python3 manage.py loaddata data.json. This translates the data loaded from the local sqlite3 database and loads it to the heroku postgre database. Unless the translating is done when you dump the data. Regardless, this synchronizes the heroku data with the local data.
I haven't tested synchronizing the local data with the heroku data, but I'm sure it'll work the same way: heroku run python3 manage.py dumpdata --exclude contenttypes > data.json and then git fetch from heroku (I've never fetched before to sync a directory with what's on github but it should be straightforward).
That's all there is to it. If I locally change the name of a project that I worked on, update the date it was last worked on, and write a few more paragraphs on the work process, and I don't want to redo all of that in the heroku shell, then I just synchronize by dumping the data, pushing it to heroku, and loading it there.
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I've been stuck on an issue for a while where I have a model that I've created locally (class User(AbstractUser)), ran "python manage.py makemigrations" and "python manage.py migrate", which works and interacts correctly with the django server when run locally.
When I push this to heroku however, I receive an error response to certain api requests which essentially say "relation "app_user" does not exist". I assumed this was because somehow the postgreSQL db didn't receive the migrations when the app was deployed to heroku. After logging into the db I noticed that it had a few other tables, including "auth_user" (I assume this is a default django table), but not "app_user". I have done "heroku run bash" and "python manage.py migrate" in an attempt to migrate the changes to the postgreSQL db, but this doesn't have any effect.
I'm not sure if this will be useful but the postgreSQL server I'm using is the standard Heroku Postgres Hobby Dev add-on.
My questions are:
Should running "python manage.py migrate" on heroku update the postgreSQL database? If so, how does this work?
Given that the migrations are all on heroku, how can I manually update the postgreSQL with the migrations?
Fixed by deleting old heroku db and creating a new one. Unsure what exactly caused the issue above but I feel it may be because we deleted all migrations on the repo at some point in the past (to start from scratch), which meant the current db state was not applicable to migrations in the repo and so could not be applied. After doing this, running migrate on the remote server works perfectly.
I have a learning project deployed on Heroku. It had a Postgres database provisioned. I introduced some major changes in the models of my Django project and destroyed the old database and provisioned a new one, which is totally empty, but it is not working like an empty database.
When I run the command heroku run python manage.py makemigrations, I get the error message
You are trying to add a non-nullable field....
Why am I getting this message when I have destroyed the old database?
First of all, you should never run manage.py makemigrations on Heroku.
By the time your code gets there no model changes should exist to generate new migrations. Run makemigrations locally to create migration files. Run migrate locally and on Heroku to apply migrations to your database.
Now that that's out of the way, this is likely caused by existing migrations files, not anything in your database. If you truly want to start over you can delete the files from each of yours apps' migrations/ directories.
Finally, there is no need to destroy and reprovision your database to reset it. Instead you can use heroku pg:reset:
The PostgreSQL user your database is assigned doesn’t have permission to create or drop databases. To drop and recreate your database use pg:reset.
use this command
heroku pg:reset
I'm new to Django but I'm deploying a Django-based website to Heroku, using Postgresql. The deployment was successful, and the website is online and has established connection with the database. However, none of the data from my local database has migrated to the heroku database, causing it to be a blank database. If I go into the admin section and manually input a datapoint, it appears on my site, so I know that database is correctly serving data. What is the proper way for migrating data from your local database to your online, heroku version of the database? I thought the following code would migrate the data:
heroku run python manage.py makemigrations
heroku run python manage.py migrate
But apparently I'm missing something.
make migrations will create a migration that contains your schema, but no data. The migrate command applies the migration to the database.
In order to provide data to be sent over as part of the migrate command you need to either create a data migration or use a fixture.
Another option you have is to dump your local database and do an import into Heroku Postgres
All in all, it depends on how much local data you have that you want copied over. If its only a few rows, I would use either a data migration or a fixture, if its 100s or 1000s of rows an export/import of your dataset is your best bet.
I've just upgraded my project to Django 1.8.4. I've never used migrations in this project before. I discovered that I had to explicitly run the "makemigrations" command against four of my apps since they contained foreign keys to the auth_user table. Do I need to run the makemigrations command against my other six applications? The reason I ask is because the documents say,
If your app already has models and database tables, and doesn’t have migrations yet (for example, you created it against a previous Django version), you’ll need to convert it to use migrations"
However, when I ran the command against my "home" app, I received this message:
No changes detected in app 'home'
When converting a project to Django 1.8, should you run the makemigrations command against all of your apps and then run "migrate --fake-initial" if the actual database tables already exist?
Thanks.
Update: Make sure that the migrations folder contains an __init__.py.
Indeed, there are many times, I have to delete and recreate my development database.
During this procedure, I have encountered the same issue especially after upgrading to Django 1.8.* / 1.9.*.
In my script, after deleting the contents of my migrations folders, I am running makemigrations in all my applications separately simultaneously.
./manage.py makemigrations <myapp1> <myapp2> ... <myappN>
Before that, I backup all my data:
./manage.py dumpdata --exclude auth.permission --exclude contenttypes --exclude admin.LogEntry --indent 2 > db.json
I made many changes in my django app and when working locally i reset the database, deleted the migration and reseted south, recreated everything all over and it worked fine.
when trying to do the same in Heroku,
after droping the database using:
heroku pg:reset DATABASE
and also reseting south using:
heroku run ./manage.py reset south
and then pushing the Django app when looking at the heroku migration list using:
heroku run ./manage.py migrate --list
i can still see all of the old imgration,
though they are empty-- no * in the ()
so even after doing
heroku run python ./manage.py migrate accounts --fake
i still get migration errors:
DatabaseError at /admin/accounts/userprofile/
****relation "accounts_userprofile" does not exist
LINE 1: SELECT COUNT(*) FROM "accounts_userprofile"****
what can i do to solve it? is there a wayy to remove old migrations in heroku and just do it simple like when working locally by starting all over again?
or is their any other solution?
--fake is used when the database tables already exists and you no longer need to actually migrate the real database. As the tables don't exist, you should just run migrate without --fake.