Fix API compatibility and add user/role/permission and asset import/export

backend_new/app/db/session.py

@@ -0,0 +1,70 @@
+"""
+数据库会话管理
+"""
+from typing import AsyncGenerator
+from sqlalchemy.ext.asyncio import create_async_engine, AsyncSession, async_sessionmaker
+from app.core.config import settings
+from app.db.base import Base
+
+# 创建异步引擎
+engine = create_async_engine(
+    settings.DATABASE_URL,
+    echo=settings.DATABASE_ECHO,
+    pool_pre_ping=True,
+    pool_size=50,  # 从20增加到50，提高并发性能
+    max_overflow=10,  # 从0增加到10，允许峰值时的额外连接
+)
+
+# 创建异步会话工厂
+async_session_maker = async_sessionmaker(
+    engine,
+    class_=AsyncSession,
+    expire_on_commit=False,
+    autocommit=False,
+    autoflush=False,
+)
+
+
+async def get_db() -> AsyncGenerator[AsyncSession, None]:
+    """
+    获取数据库会话
+
+    Yields:
+        AsyncSession: 数据库会话
+    """
+    async with async_session_maker() as session:
+        try:
+            yield session
+            await session.commit()
+        except Exception:
+            await session.rollback()
+            raise
+        finally:
+            await session.close()
+
+
+async def init_db() -> None:
+    """
+    初始化数据库（创建所有表）
+    注意：生产环境应使用Alembic迁移
+    """
+    async with engine.begin() as conn:
+        # 导入所有模型以确保它们被注册
+        from app.models import user, asset, device_type, organization
+
+        # 创建所有表
+        await conn.run_sync(Base.metadata.create_all)
+
+
+async def close_db() -> None:
+    """关闭数据库连接"""
+    await engine.dispose()
+
+
+__all__ = [
+    "engine",
+    "async_session_maker",
+    "get_db",
+    "init_db",
+    "close_db",
+]