Initial commit: 浼佷笟寰俊 AI 鏈哄櫒浜哄姪鐞?MVP

Co-authored-by: Cursor <cursoragent@cursor.com>

backend/app/database.py

@@ -0,0 +1,27 @@
+"""异步数据库会话，DATABASE_URL 来自环境变量。"""
+from collections.abc import AsyncGenerator
+
+from sqlalchemy.ext.asyncio import AsyncSession, async_sessionmaker, create_async_engine
+
+from app.config import settings
+
+engine = create_async_engine(
+    settings.database_url,
+    echo=False,
+    pool_pre_ping=True,
+)
+async_session_factory = async_sessionmaker(
+    engine, class_=AsyncSession, expire_on_commit=False, autoflush=False
+)
+
+
+async def get_db() -> AsyncGenerator[AsyncSession, None]:
+    async with async_session_factory() as session:
+        try:
+            yield session
+            await session.commit()
+        except Exception:
+            await session.rollback()
+            raise
+        finally:
+            await session.close()