database/database.py

import os
from sqlalchemy import create_engine
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy.orm import sessionmaker

SQLALCHEMY_DATABASE_URL = os.getenv("DATABASE_URL", "sqlite:///./taxpro.db")

# Some cloud providers use postgres:// instead of postgresql://
if SQLALCHEMY_DATABASE_URL.startswith("postgres://"):
    SQLALCHEMY_DATABASE_URL = SQLALCHEMY_DATABASE_URL.replace("postgres://", "postgresql://", 1)

if SQLALCHEMY_DATABASE_URL.startswith("sqlite"):
    engine = create_engine(SQLALCHEMY_DATABASE_URL, connect_args={"check_same_thread": False})
else:
    engine = create_engine(SQLALCHEMY_DATABASE_URL)

SessionLocal = sessionmaker(autocommit=False, autoflush=False, bind=engine)

Base = declarative_base()

def get_db():
    db = SessionLocal()
    try:
        yield db
    finally:
        db.close()