问Flask SQLAlchemy -仅为当前会话设置expire_on_commit=FalseENexpire_on_commit是sqlalchemy.orm.sessio...
#创建异步引擎和会话DATABASE_URL ="mysql+asyncmy://username:password@localhost/mydatabase"engine= create_async_engine(DATABASE_URL, echo=True) AsyncSessionLocal= sessionmaker(bind=engine, class_=AsyncSession, expire_on_commit=False) asyncdefinit_db(): async with engine.begin() as conn: await...
bind=engine, autoflush=False, expire_on_commit=False )returnengine, db_session#异步处理async_engine, async_session =create_engine_and_session(settings.DB_URI_ASYNC) asyncdefget_db() ->AsyncGenerator[AsyncSession, None]:"""创建一个 SQLAlchemy 数据库会话-异步处理."""async with async_session()...
engine = create_async_engine(DATABASE_URL, echo=True) AsyncSessionLocal = sessionmaker(bind=engine, class_=AsyncSession, expire_on_commit=False) async def init_db(): async with engine.begin() as conn: await conn.run_sync(Base.metadata.create_all) # 示例:如何插入数据并进行查询 async def ...
engine = create_engine(dbname, echo=False) DBSession.remove() DBSession.configure(bind=engine, autoflush=False, expire_on_commit=False) Base.metadata.drop_all(engine) Base.metadata.create_all(engine) def test_sqlalchemy_orm(n=100000):
expire_on_commit=False # 使用示例 async def get_users(): async with AsyncSessionLocal() as session: result = await session.execute(select(User)) users = result.scalars().all() return users 8. 最佳实践 使用上下文管理器管理会话: python ...
>>> session = Session(engine, expire_on_commit=False) >>> existing_account = session.scalar(select(Account).filter_by(identifier="account_01")) BEGIN (implicit) SELECT account.id, account.identifier FROM account WHERE account.identifier = ?
并且重要的是,将 expire_on_commit 设置为 False - 当使用分离的对象时,对象需要重新加载数据的最常见原因是因为它们在上次调用 Session.commit() 时过期了。当处理分离的对象时,不应使用此过期;因此,Session.expire_on_commit 参数应设置为 False。通过防止对象在事务外过期,加载的数据将保持存在,并且在访问该数据...
call(), init(), add(), add_all(), autoflush, begin(), begin_nested(), bind, bulk_insert_mappings(), bulk_save_objects(), bulk_update_mappings(), close(), close_all(), commit(), configure(), connection(), delete(), deleted, dirty, execute(), expire(), expire_all(), expunge...
autocommit=False, expire_on_commit=True, info=None, **kw): 5、create an instance of the mapped class: 例,增: try: stu1 = Student() = 'tom'#属性赋值 stu1.age = 20 # student.id = 100#有自增字段和有默认值的可不加 ...