初始化提交

backend/app/db/session.py

@@ -0,0 +1,43 @@
+"""异步数据库会话。"""
+
+from collections.abc import AsyncGenerator
+
+from sqlalchemy.ext.asyncio import (
+    AsyncEngine,
+    AsyncSession,
+    async_sessionmaker,
+    create_async_engine,
+)
+
+from app.core.config import settings
+
+
+def create_engine_from_url(database_url: str) -> AsyncEngine:
+    connect_args: dict[str, object] = {}
+    if database_url.startswith("sqlite"):
+        connect_args["check_same_thread"] = False
+    return create_async_engine(
+        database_url,
+        echo=settings.debug,
+        pool_pre_ping=True,
+        connect_args=connect_args,
+    )
+
+
+engine = create_engine_from_url(settings.resolved_database_url)
+AsyncSessionLocal = async_sessionmaker(engine, expire_on_commit=False, class_=AsyncSession)
+
+
+def configure_database(database_url: str) -> None:
+    global AsyncSessionLocal, engine
+    engine = create_engine_from_url(database_url)
+    AsyncSessionLocal = async_sessionmaker(engine, expire_on_commit=False, class_=AsyncSession)
+
+
+async def get_session() -> AsyncGenerator[AsyncSession, None]:
+    async with AsyncSessionLocal() as session:
+        yield session
+
+
+async def close_engine() -> None:
+    await engine.dispose()