完成了数据库相关代码

services/db.py

@@ -0,0 +1,67 @@
+from sqlalchemy.ext.asyncio import AsyncEngine, create_async_engine, AsyncSession
+from sqlalchemy.orm import sessionmaker
+from ..models.user import Base, User, UserRole
+from sqlalchemy import select
+from contextlib import asynccontextmanager
+from config import SYSTEM_ADMIN_CONFIG, DATABASE_CONFIG
+from services.auth import get_password_hash
+from typing import AsyncGenerator
+
+# 全局数据库引擎实例
+_engine: AsyncEngine | None = None
+
+def create_db_engine() -> AsyncEngine:
+    """创建数据库引擎"""
+    return create_async_engine(
+        f"mysql+asyncmy://{DATABASE_CONFIG['user']}:{DATABASE_CONFIG['password']}@"
+        f"{DATABASE_CONFIG['host']}:{DATABASE_CONFIG['port']}/{DATABASE_CONFIG['database']}",
+        echo=True
+    )
+
+def get_db_engine() -> AsyncEngine:
+    """获取全局数据库引擎实例"""
+    if _engine is None:
+        raise RuntimeError("Database engine not initialized")
+    return _engine
+
+@asynccontextmanager
+async def get_db_session() -> AsyncGenerator[AsyncSession, None]:
+    """获取数据库会话"""
+    async with AsyncSession(get_db_engine()) as session:
+        try:
+            yield session
+            await session.commit()
+        except Exception:
+            await session.rollback()
+            raise
+
+async def init_db(engine: AsyncEngine):
+    """初始化数据库"""
+    global _engine
+    _engine = engine
+    
+    async with engine.begin() as conn:
+        # 创建所有表
+        await conn.run_sync(Base.metadata.create_all)
+
+        # 检查系统管理员是否存在
+        result = await conn.execute(
+            select(User).where(User.role == UserRole.SYSTEM_ADMIN)
+        )
+        if not result.scalars().first():
+            # 创建默认系统管理员
+            admin = User(
+                username=SYSTEM_ADMIN_CONFIG['username'],
+                password=get_password_hash(SYSTEM_ADMIN_CONFIG['password']),
+                role=UserRole.SYSTEM_ADMIN,
+                description=SYSTEM_ADMIN_CONFIG['description']
+            )
+            conn.add(admin)
+            await conn.commit()
+
+async def close_db_connection():
+    """关闭数据库连接"""
+    global _engine
+    if _engine is not None:
+        await _engine.dispose()
+        _engine = None

services/init_db.py

@@ -1,26 +0,0 @@
-from sqlalchemy.ext.asyncio import AsyncEngine
-from ..models.user import Base, User, UserRole
-from sqlalchemy import select
-from config import SYSTEM_ADMIN_CONFIG
-from services.auth import get_password_hash
-
-async def init_db(engine: AsyncEngine):
-    """初始化数据库"""
-    async with engine.begin() as conn:
-        # 创建所有表
-        await conn.run_sync(Base.metadata.create_all)
-
-        # 检查系统管理员是否存在
-        result = await conn.execute(
-            select(User).where(User.role == UserRole.SYSTEM_ADMIN)
-        )
-        if not result.scalars().first():
-            # 创建默认系统管理员
-            admin = User(
-                username=SYSTEM_ADMIN_CONFIG['username'],
-                password=get_password_hash(SYSTEM_ADMIN_CONFIG['password']),
-                role=UserRole.SYSTEM_ADMIN,
-                description=SYSTEM_ADMIN_CONFIG['description']
-            )
-            conn.add(admin)
-            await conn.commit()