I have a very simple and silly problem but I don't know what I'm missing. Basically, the way I've currently written my manage app, it seems flask migrate always creates an absolute migration and not just a change-set to migrate from the previous schema to the current one.
For example, if I delete my migrations and spin a brand new DB and I then do manage db migrate followed by manage db upgrade all works. If I then make a change to a db.Model table and then do manage db migrate I don't get an error.
However, the new migration script points to the previous one but isn't just the diff needed to get the database from the previous schema state to the new one but a full (absolute) migration starting from an empty schema - as in, it would try to create the tables from scratch again (with the change) and not just for example apply the change to the already created schema. That is, even though the migration is linked to the previous one, it hasn't taken into account what the previous migration has been applied. This means they cannot be chained because for example the second migration will attempt to create tables again and so manage db upgrade fails when called the second time.
My manage app looks like this:
from flask_migrate import Migrate, MigrateCommand
from src.common.db import db
from src.common.flaskery import global_flask_app, global_flask_manager
app = global_flask_app(__name__)
migrate = Migrate(app, db)
manager = global_flask_manager(__name__)
manager.add_command('db', MigrateCommand)
from src.db.models import *
def main():
manager.run()
if __name__ == '__main__':
main()
Similar: Flask Migrate using different postgres schemas ( __table_args__ = {'schema': 'test_schema']})
So in your migrations/env.py, you need to add include_schemas=True to the config as below:
context.configure(connection=connection,
target_metadata=target_metadata,
process_revision_directives=process_revision_directives,
include_schemas=True,
**current_app.extensions['migrate'].configure_args)