Migrate database from SQLite to PostgreSQL

[johndpjr]

Context

SQLite is good for a single-file database solution; it won't scale well for our needs since we'll be having multiple webscrapers working at once and we'll need this database to be hosted on some URL somewhere. PostgreSQL is another SQL-based database solution that handles concurrency and scales better than SQLite. We were using SQLAlchemy as a database abstraction layer which allows us to write SQLAlchemy code without having to worry about the underlying implementation (e.g. SQLite, PostgreSQL, etc.).

TODO

• [x] Check out backend/app/database/database.py for the migration entry point and some additional information
• [x] Install the database driver for PostgreSQL by adding psycopg2==2.9.8 to the requirements.txt file and running pip3 install -r requirements.txt
• [x] Follow the SQLAlchemy connection tutorial
• [x] Comment below on actionable steps that developers need to complete to setup their local PostgreSQL instance

Notes

You don't need to set up a remote PostgreSQL instance. A local one will work for now.

[johndpjr]

Waiting for the following things to do before merging:

• Better-organized/refactored repo
• Having PostgreSQL documentation that details steps needed for migration
• Functioning DO instance
• Configuration b/t SQLite and PostgreSQL database types