初始话项目框架

app/core/database.py

@@ -0,0 +1,59 @@
+from collections.abc import AsyncGenerator
+from typing import Optional
+
+from sqlalchemy.ext.asyncio import (
+    AsyncEngine,
+    AsyncSession,
+    async_sessionmaker,
+    create_async_engine,
+)
+from sqlalchemy.orm import DeclarativeBase
+
+from app.config import settings
+from app.core.logger import log
+
+# 全局引擎和会话工厂
+engine: Optional[AsyncEngine] = None
+async_session_factory: Optional[async_sessionmaker[AsyncSession]] = None
+
+
+class Base(DeclarativeBase):
+    """ORM 声明基类"""
+    pass
+
+
+async def init_db() -> None:
+    """初始化数据库引擎和会话工厂"""
+    global engine, async_session_factory
+
+    engine = create_async_engine(
+        settings.database_url,
+        pool_size=settings.db_pool_size,
+        max_overflow=settings.db_max_overflow,
+        pool_recycle=settings.db_pool_recycle,
+        echo=settings.env == "dev",
+    )
+    async_session_factory = async_sessionmaker(engine, expire_on_commit=False)
+    log.info("数据库连接池已初始化")
+
+
+async def close_db() -> None:
+    """关闭数据库引擎，释放连接池"""
+    global engine
+    if engine:
+        await engine.dispose()
+        log.info("数据库连接池已关闭")
+
+
+async def get_db() -> AsyncGenerator[AsyncSession, None]:
+    """依赖注入：提供异步数据库会话，自动 commit/rollback/close"""
+    if async_session_factory is None:
+        raise RuntimeError("数据库未初始化，请先调用 init_db()")
+
+    async with async_session_factory() as session:
+        try:
+            yield session
+            await session.commit()
+        except Exception:
+            await session.rollback()
+            raise