FastAPI SQLAlchemy MIgrations Guide

Step 1: Getting Up the Enviroment

mkdir app
cd app

Now, create a virtual enviroment to isolate our project dependencies:

python -m venv venv
source venv/bin/activate # On Windows, use "venv\Scripts\activate"

Step 2: Installing Required Packages

pip install fastapi[all] uvicorn[standart] sqlalchemy alembic

Step 3: Creating the database

How that we have defined our model, let`s create the SQLite database and tables

alembic init alembic

Step 3: Auto Migration

if you alembic handles migrations follow this method: In the alembic folder edit env.py and find target_metadata line and edit like the following

# alembic/env.py

# NOTE we addedd
from app.db.base import Base
target_metadata = Base.metadata

Step 5: Configuring Alembic

Open the alembic.ini file in the alembic directory and make the following changes:

# alembic.ini
[alembic]
script_location = alembic

sqlalchmey.url = sqlite:///./sqlite3.db # Replace with your database URL if different

Step 6: Generating a Migration

alembic revision --autogenerate -m "Initial migration"

Step 7: Applying the Migration

alembic upgrade head

Step 8: Run project

python main.py