mitlist/be/app/database.py

46 lines
1.3 KiB
Python

from sqlalchemy.ext.asyncio import create_async_engine, AsyncSession
from sqlalchemy.orm import sessionmaker, declarative_base
from app.config import settings
if not settings.DATABASE_URL:
raise ValueError("DATABASE_URL is not configured in settings.")
engine = create_async_engine(
settings.DATABASE_URL,
echo=False,
future=True,
pool_recycle=3600,
pool_pre_ping=True
)
AsyncSessionLocal = sessionmaker(
bind=engine,
class_=AsyncSession,
expire_on_commit=False,
autoflush=False,
autocommit=False,
)
Base = declarative_base()
async def get_session() -> AsyncSession: # type: ignore
"""
Dependency function that yields an AsyncSession for read-only operations.
Ensures the session is closed after the request.
"""
async with AsyncSessionLocal() as session:
yield session
async def get_transactional_session() -> AsyncSession: # type: ignore
"""
Dependency function that yields an AsyncSession and manages a transaction.
Commits the transaction if the request handler succeeds, otherwise rollbacks.
Ensures the session is closed after the request.
This follows the FastAPI-DB strategy for endpoint-level transaction management.
"""
async with AsyncSessionLocal() as session:
async with session.begin():
yield session
get_db = get_session