在FastAPI中连接数据库的最佳方法是什么?

我在FastAPI中找到了两种使用数据库的方法。有什么根本的区别吗?如果是,哪种方法更可取?

方法1 这可以在官方的FastAPI全栈中找到 example :

from fastapi import Depends
from sqlalchemy.orm import sessionmaker
from sqlalchemy import create_engine

engine = create_engine(SQLALCHEMY_DATABASE_URI, pool_pre_ping=True)
SessionLocal = sessionmaker(autocommit=False, autoflush=False, bind=engine)

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


def get_current_user(
    db: Session = Depends(get_db), token: str = Depends(reusable_oauth2)
) -> models.User:
    ...

方法2 以下方法在官方网站上找到 FastAPI docs ,一些博客,也在 fastapi_users 软件包文档:

import databases

DATABASE_URL = "sqlite:///./test.db"
database = databases.Database(DATABASE_URL)

@app.on_event("startup")
async def startup():
    await database.connect()


@app.on_event("shutdown")
async def shutdown():
    await database.disconnect()

编辑(2021-09-06)-方法3

天戈洛自己在新的SQLModel包文档中推荐的另一种方式。这似乎只是上面第一种方法的变体,但为了完整性:

https://sqlmodel.tiangolo.com/tutorial/fastapi/session-with-dependency/

sqlite_file_name = "database.db"
sqlite_url = f"sqlite:///{sqlite_file_name}"

connect_args = {"check_same_thread": False}
engine = create_engine(sqlite_url, echo=True, connect_args=connect_args)

def get_session():
    with Session(engine) as session:
        yield session

# Code here omitted 👈

@app.post("/heroes/", response_model=HeroRead)
def create_hero(*, session: Session = Depends(get_session), hero: HeroCreate):
    db_hero = Hero.from_orm(hero)
    session.add(db_hero)
    session.commit()
    session.refresh(db_hero)
    return db_hero