# app/api/db/database.py
from sqlalchemy import create_engine
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy.orm import sessionmaker
SQLALCHEMY_DATABASE_URL = "sqlite:///./blog_app.db"
engine = create_engine(
    SQLALCHEMY_DATABASE_URL, connect_args={"check_same_thread": False}
)
SessionLocal = sessionmaker(autocommit=False, autoflush=False, bind=engine)
Base = declarative_base()
```
This code defines the necessary components for working with a SQLite database using SQLAlchemy in a FastAPI application named "blog_app".
With this setup, you can define your database models by inheriting from `Base` and create database sessions using `SessionLocal`. The `engine` instance can be used for various database operations, such as creating tables or executing raw SQL queries.