Setup

SQLAlchemy Setup Verification

Verify that SQLAlchemy is correctly configured and the database connection works.

Verification Steps

1. Check Dependencies

Read requirements.txt or pyproject.toml and verify:

SQLite needs no driver — it's built into Python.

2. Check Database URI

Verify the connection string format:

# SQLite (file-based)
'sqlite:///instance/app.db'
'sqlite:///path/to/database.db'
'sqlite:///:memory:'  # In-memory (testing)

# PostgreSQL
'postgresql://user:password@host:5432/dbname'
'postgresql+psycopg2://user:password@host/dbname'

# MySQL
'mysql+pymysql://user:password@host/dbname'

Ensure the URI comes from environment variables, not hardcoded:

# Good
SQLALCHEMY_DATABASE_URI = os.environ.get('DATABASE_URL', 'sqlite:///app.db')

# Bad
SQLALCHEMY_DATABASE_URI = 'postgresql://admin:secret@prod.example.com/mydb'

3. Check Initialization Pattern

For Flask-SQLAlchemy:

# models.py — create db instance
db = SQLAlchemy()

# app.py — bind to app in factory
def create_app():
    app = Flask(__name__)
    db.init_app(app)
    with app.app_context():
        db.create_all()
    return app

For standalone SQLAlchemy:

from sqlalchemy import create_engine
from sqlalchemy.orm import sessionmaker, DeclarativeBase

engine = create_engine(DATABASE_URL)
Session = sessionmaker(bind=engine)

class Base(DeclarativeBase):
    pass

4. Check Model Definitions

Verify models have:

• Primary key defined
• Proper column types and constraints
• Relationships with correct foreign keys
• __tablename__ set explicitly

5. Common Setup Issues

What This Skill Does NOT Cover

• Flask application structure (see flask-dev plugin)
• Deployment database setup (belongs in project template)
• Database administration (see postgresql-provision plugin)