Flask with DB deployed to Heroku

Name of the app: flask-db-heroku-project

Website: https://flask-db-heroku-project.herokuapp.com/

Inside python of Heroku project

$ heroku run python

Inside DB

$ heroku pg:psql --app <name of the app>

select * from <table name>;

Pitfalls & Tricks

• Specifying a Python version
• Specifying a Python Runtime
• set SQLAlchemy==1.3.24 and not SQLAlchemy==1.4.< with pip install SQLAlchemy==1.3.24
• Use SQL with flask_sqlalchemy
• What does Autogenerate Detect (and what does it not detect?) during flask db migrate -m "...migration message"
• Show tables in your db: First, choose your database:

$ \c database_name

Then, this shows all tables in the current schema:

$ \dt

• How I solved issue with:

$ INFO  [alembic.env] No changes in schema detected.

I created another project connected to the same DB. Then, I copied some files of versions... and that's it. It worked after that in the current project. I do not know exactly what was a problem.

Credits

• YouTube | Build & Deploy A Python Web App | Flask, Postgres & Heroku
• YouTube | REST API With Flask & SQL Alchemy
• Migration with flask-migrate
• blog | Developing a Flask Web App with a PostreSQL Database - Making all the Possible Errors
• blog | Working with PostgreSQL in Python
• github | psycopg2