diff options
Diffstat (limited to 'test/ext/mypy/plain_files/async_sessionmaker.py')
-rw-r--r-- | test/ext/mypy/plain_files/async_sessionmaker.py | 79 |
1 files changed, 79 insertions, 0 deletions
diff --git a/test/ext/mypy/plain_files/async_sessionmaker.py b/test/ext/mypy/plain_files/async_sessionmaker.py new file mode 100644 index 000000000..01a26d035 --- /dev/null +++ b/test/ext/mypy/plain_files/async_sessionmaker.py @@ -0,0 +1,79 @@ +"""Illustrates use of the sqlalchemy.ext.asyncio.AsyncSession object +for asynchronous ORM use. + +""" +from __future__ import annotations + +import asyncio +from typing import List +from typing import TYPE_CHECKING + +from sqlalchemy import ForeignKey +from sqlalchemy.ext.asyncio import async_sessionmaker +from sqlalchemy.ext.asyncio import create_async_engine +from sqlalchemy.future import select +from sqlalchemy.orm import DeclarativeBase +from sqlalchemy.orm import Mapped +from sqlalchemy.orm import mapped_column +from sqlalchemy.orm import relationship + +if TYPE_CHECKING: + from sqlalchemy import ScalarResult + + +class Base(DeclarativeBase): + pass + + +class A(Base): + __tablename__ = "a" + + id: Mapped[int] = mapped_column(primary_key=True) + data: Mapped[str] + bs: Mapped[List[B]] = relationship() + + +class B(Base): + __tablename__ = "b" + id: Mapped[int] = mapped_column(primary_key=True) + a_id = mapped_column(ForeignKey("a.id")) + data: Mapped[str] + + +async def async_main() -> None: + """Main program function.""" + + engine = create_async_engine( + "postgresql+asyncpg://scott:tiger@localhost/test", + echo=True, + ) + + async with engine.begin() as conn: + await conn.run_sync(Base.metadata.drop_all) + async with engine.begin() as conn: + await conn.run_sync(Base.metadata.create_all) + + async_session = async_sessionmaker(engine, expire_on_commit=False) + + async with async_session.begin() as session: + session.add_all( + [ + A(bs=[B(), B()], data="a1"), + A(bs=[B()], data="a2"), + A(bs=[B(), B()], data="a3"), + ] + ) + + async with async_session() as session: + + result = await session.execute(select(A).order_by(A.id)) + + r: ScalarResult[A] = result.scalars() + a1 = r.one() + + a1.data = "new data" + + await session.commit() + + +asyncio.run(async_main()) |