完成后端数据库连接配置

backend/app/core/database/mysql.py

@@ -0,0 +1,193 @@
+"""
+MySQL 数据库连接管理模块
+
+提供结构化数据的存储和查询功能
+"""
+import logging
+from contextlib import asynccontextmanager
+from typing import Any, AsyncGenerator, Dict, List, Optional
+
+from sqlalchemy import (
+    Column,
+    DateTime,
+    Enum as SQLEnum,
+    Float,
+    Integer,
+    String,
+    Text,
+    create_engine,
+)
+from sqlalchemy.ext.asyncio import AsyncSession, async_sessionmaker, create_async_engine
+from sqlalchemy.orm import DeclarativeBase, sessionmaker
+from sqlalchemy.sql import select
+
+from app.config import settings
+
+logger = logging.getLogger(__name__)
+
+
+class Base(DeclarativeBase):
+    """SQLAlchemy 声明基类"""
+    pass
+
+
+class MySQLDB:
+    """MySQL 数据库管理类"""
+
+    def __init__(self):
+        # 异步引擎 (用于 FastAPI 异步操作)
+        self.async_engine = create_async_engine(
+            settings.mysql_url,
+            echo=settings.DEBUG,  # SQL 日志
+            pool_pre_ping=True,   # 连接前检测
+            pool_size=10,
+            max_overflow=20,
+        )
+
+        # 异步会话工厂
+        self.async_session_factory = async_sessionmaker(
+            bind=self.async_engine,
+            class_=AsyncSession,
+            expire_on_commit=False,
+            autocommit=False,
+            autoflush=False,
+        )
+
+        # 同步引擎 (用于 Celery 同步任务)
+        self.sync_engine = create_engine(
+            settings.mysql_url.replace("mysql+pymysql", "mysql"),
+            echo=settings.DEBUG,
+            pool_pre_ping=True,
+            pool_size=5,
+            max_overflow=10,
+        )
+
+        # 同步会话工厂
+        self.sync_session_factory = sessionmaker(
+            bind=self.sync_engine,
+            autocommit=False,
+            autoflush=False,
+        )
+
+    async def init_db(self):
+        """初始化数据库，创建所有表"""
+        try:
+            async with self.async_engine.begin() as conn:
+                await conn.run_sync(Base.metadata.create_all)
+            logger.info("MySQL 数据库表初始化完成")
+        except Exception as e:
+            logger.error(f"MySQL 数据库初始化失败: {e}")
+            raise
+
+    async def close(self):
+        """关闭数据库连接"""
+        await self.async_engine.dispose()
+        self.sync_engine.dispose()
+        logger.info("MySQL 数据库连接已关闭")
+
+    @asynccontextmanager
+    async def get_session(self) -> AsyncGenerator[AsyncSession, None]:
+        """获取异步数据库会话"""
+        session = self.async_session_factory()
+        try:
+            yield session
+            await session.commit()
+        except Exception:
+            await session.rollback()
+            raise
+        finally:
+            await session.close()
+
+    async def execute_query(
+        self,
+        query: str,
+        params: Optional[Dict[str, Any]] = None
+    ) -> List[Dict[str, Any]]:
+        """
+        执行原始 SQL 查询
+
+        Args:
+            query: SQL 查询语句
+            params: 查询参数
+
+        Returns:
+            查询结果列表
+        """
+        async with self.get_session() as session:
+            result = await session.execute(select(text(query)), params or {})
+            rows = result.fetchall()
+            return [dict(row._mapping) for row in rows]
+
+    async def execute_raw_sql(
+        self,
+        sql: str,
+        params: Optional[Dict[str, Any]] = None
+    ) -> Any:
+        """
+        执行原始 SQL 语句 (INSERT/UPDATE/DELETE)
+
+        Args:
+            sql: SQL 语句
+            params: 语句参数
+
+        Returns:
+            执行结果
+        """
+        async with self.get_session() as session:
+            result = await session.execute(text(sql), params or {})
+            await session.commit()
+            return result.lastrowid if result.lastrowid else result.rowcount
+
+
+# ==================== 预定义的数据模型 ====================
+
+class DocumentTable(Base):
+    """文档元数据表 - 存储已解析文档的基本信息"""
+    __tablename__ = "document_tables"
+
+    id = Column(Integer, primary_key=True, autoincrement=True)
+    table_name = Column(String(255), unique=True, nullable=False, comment="表名")
+    display_name = Column(String(255), comment="显示名称")
+    description = Column(Text, comment="表描述")
+    source_file = Column(String(512), comment="来源文件")
+    column_count = Column(Integer, default=0, comment="列数")
+    row_count = Column(Integer, default=0, comment="行数")
+    file_size = Column(Integer, comment="文件大小(字节)")
+    created_at = Column(DateTime, comment="创建时间")
+    updated_at = Column(DateTime, comment="更新时间")
+
+
+class DocumentField(Base):
+    """文档字段表 - 存储每个表的字段信息"""
+    __tablename__ = "document_fields"
+
+    id = Column(Integer, primary_key=True, autoincrement=True)
+    table_id = Column(Integer, nullable=False, comment="所属表ID")
+    field_name = Column(String(255), nullable=False, comment="字段名")
+    field_type = Column(String(50), comment="字段类型")
+    field_description = Column(Text, comment="字段描述/语义")
+    is_key_field = Column(Integer, default=0, comment="是否主键")
+    is_nullable = Column(Integer, default=1, comment="是否可空")
+    sample_values = Column(Text, comment="示例值(逗号分隔)")
+    created_at = Column(DateTime, comment="创建时间")
+
+
+class TaskRecord(Base):
+    """任务记录表 - 存储异步任务信息"""
+    __tablename__ = "task_records"
+
+    id = Column(Integer, primary_key=True, autoincrement=True)
+    task_id = Column(String(255), unique=True, nullable=False, comment="Celery任务ID")
+    task_type = Column(String(50), comment="任务类型")
+    status = Column(String(50), default="pending", comment="任务状态")
+    input_params = Column(Text, comment="输入参数JSON")
+    result_data = Column(Text, comment="结果数据JSON")
+    error_message = Column(Text, comment="错误信息")
+    started_at = Column(DateTime, comment="开始时间")
+    completed_at = Column(DateTime, comment="完成时间")
+    created_at = Column(DateTime, comment="创建时间")
+
+
+# ==================== 全局单例 ====================
+
+mysql_db = MySQLDB()