docs: update project structure and add database documentation

- Add tests/ directory to .gitignore
- Document database connectivity with pyodbc and config
- Add project structure and file organization guidelines
- Update installation steps to use requirements.txt
- Document new dependencies: pandas, openpyxl, pyodbc

db/connection.py

@@ -0,0 +1,184 @@
+"""
+SQL Server 数据库连接组件
+
+提供数据库连接和查询接口
+"""
+import pyodbc
+from typing import List, Dict, Any, Optional
+import sys
+import os
+
+# 添加项目根目录到 sys.path
+project_root = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
+if project_root not in sys.path:
+    sys.path.insert(0, project_root)
+
+from config.database_config import SQL_SERVER_CONFIG
+
+
+class DatabaseConnection:
+    """SQL Server 数据库连接类"""
+
+    def __init__(self, config: Optional[Dict[str, Any]] = None):
+        """
+        初始化数据库连接
+
+        Args:
+            config: 数据库配置字典，默认使用 SQL_SERVER_CONFIG
+        """
+        self.config = config or SQL_SERVER_CONFIG
+        self.connection = None
+
+    def connect(self) -> pyodbc.Connection:
+        """
+        建立数据库连接
+
+        Returns:
+            pyodbc.Connection: 数据库连接对象
+        """
+        if self.connection is not None:
+            return self.connection
+
+        # 构建连接字符串
+        conn_str = (
+            f"DRIVER={{{self.config['driver']}}};"
+            f"SERVER={self.config['server']};"
+            f"DATABASE={self.config['database']};"
+            f"UID={self.config['username']};"
+            f"PWD={self.config['password']};"
+            f"TrustServerCertificate={self.config['TrustServerCertificate']};"
+        )
+
+        try:
+            self.connection = pyodbc.connect(conn_str)
+            print(f"成功连接到数据库: {self.config['server']}/{self.config['database']}")
+            return self.connection
+        except pyodbc.Error as e:
+            print(f"数据库连接失败: {e}")
+            raise
+
+    def disconnect(self):
+        """关闭数据库连接"""
+        if self.connection:
+            self.connection.close()
+            self.connection = None
+            print("数据库连接已关闭")
+
+    def execute_query(self, sql: str, params: Optional[tuple] = None) -> List[Dict[str, Any]]:
+        """
+        执行查询语句并返回结果
+
+        Args:
+            sql: SQL 查询语句
+            params: 查询参数（可选）
+
+        Returns:
+            List[Dict[str, Any]]: 查询结果列表，每个元素为一行数据的字典
+        """
+        if not self.connection:
+            self.connect()
+
+        cursor = self.connection.cursor()
+
+        try:
+            if params:
+                cursor.execute(sql, params)
+            else:
+                cursor.execute(sql)
+
+            # 获取列名
+            columns = [column[0] for column in cursor.description]
+
+            # 将结果转换为字典列表
+            results = []
+            for row in cursor.fetchall():
+                results.append(dict(zip(columns, row)))
+
+            return results
+
+        except pyodbc.Error as e:
+            print(f"查询执行失败: {e}")
+            raise
+        finally:
+            cursor.close()
+
+    def execute_update(self, sql: str, params: Optional[tuple] = None) -> int:
+        """
+        执行更新/插入/删除语句
+
+        Args:
+            sql: SQL 语句
+            params: 参数（可选）
+
+        Returns:
+            int: 受影响的行数
+        """
+        if not self.connection:
+            self.connect()
+
+        cursor = self.connection.cursor()
+
+        try:
+            if params:
+                cursor.execute(sql, params)
+            else:
+                cursor.execute(sql)
+
+            self.connection.commit()
+            return cursor.rowcount
+
+        except pyodbc.Error as e:
+            self.connection.rollback()
+            print(f"执行失败，已回滚: {e}")
+            raise
+        finally:
+            cursor.close()
+
+    def __enter__(self):
+        """支持 with 语句的上下文管理器入口"""
+        self.connect()
+        return self
+
+    def __exit__(self, exc_type, exc_val, exc_tb):
+        """支持 with 语句的上下文管理器出口"""
+        self.disconnect()
+
+
+# 便捷函数
+def query_production_orders(总排号_list: List[str]) -> List[Dict[str, Any]]:
+    """
+    根据总排号列表查询生产订单号
+
+    Args:
+        总排号_list: 总排号列表
+
+    Returns:
+        List[Dict[str, Any]]: 查询结果
+    """
+    db = DatabaseConnection()
+
+    # 构建占位符字符串
+    placeholders = ','.join(['?' for _ in 总排号_list])
+
+    sql = f"""
+    SELECT [总排号], [生产订单号], [序号], [订单号], [客户名称], [产品型号]
+    FROM [productionContractData].[26年压力表合同数据]
+    WHERE [总排号] IN ({placeholders})
+    ORDER BY [序号]
+    """
+
+    try:
+        results = db.execute_query(sql, tuple(总排号_list))
+        return results
+    finally:
+        db.disconnect()
+
+
+def get_connection() -> DatabaseConnection:
+    """
+    获取数据库连接实例
+
+    Returns:
+        DatabaseConnection: 数据库连接对象
+    """
+    return DatabaseConnection()