1 pip3 install sqlalchemy 组成部分： Engine，框架的引擎 Connection Pooling ，数据库...
db_session=async_sessionmaker( 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....
class_=AsyncSession, 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 from contextlib import contextmanage...
#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...
这个AsyncSession是使用以下方式配置的Session.expire_on_commit设置为false,以便我们可以在调用AsyncSession.commit(),如我们访问属性::的末尾那行所示 # create AsyncSession with expire_on_commit=False async_session = AsyncSession(engine, expire_on_commit=False) ...
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 example_usage(): ...
通常情况下不应该需要过期,因为在使用 asyncio 时通常应该将Session.expire_on_commit设置为False。 使用AsyncSession.refresh()可以显式加载懒加载关系,如果所需的属性名称被显式传递给Session.refresh.attribute_names,例如: 代码语言:javascript 代码运行次数:0 运行 复制 # assume a_obj is an A that has lazy ...
SessionType = scoped_session(sessionmaker(bind=engine,expire_on_commit=False)) def GetSession(): return SessionType() from contextlib import contextmanager @contextmanager def session_scope(): session = GetSession() try: yield session session.commit() ...
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 ...
configure(bind=engine, autoflush=False, expire_on_commit=False) def dropall(): Base.metadata.drop_all(engine) def createall(): Base.metadata.create_all(engine) def prep(dbname = 'sqlite:///sqlite.db', echo=False): init(dbname=dbname, echo=echo) dropall() createall() class Customer(...