89 lines
3.6 KiB
Python
89 lines
3.6 KiB
Python
# -*- coding: utf-8 -*-
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"""SQL Server 数据访问层,通过 pyodbc 按总排号批量查询新参数字段。"""
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from __future__ import annotations
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import logging
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from typing import Any
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import pyodbc
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logger = logging.getLogger(__name__)
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class DatabaseError(Exception):
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"""数据库连接或查询失败。"""
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def _build_conn_str(db_cfg: dict[str, Any]) -> str:
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parts = [
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f"DRIVER={{{db_cfg['driver']}}};",
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f"SERVER={db_cfg['server']},{db_cfg['port']};",
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f"DATABASE={db_cfg['database']};",
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f"UID={db_cfg['username']};",
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f"PWD={db_cfg['password']};",
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f"Connection Timeout={db_cfg['connect_timeout']};",
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]
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# 数据库服务器使用自签名/不受信任证书时,跳过证书链校验(连接仍保持加密)。
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# ODBC Driver 17/18 默认 Encrypt=Yes,遇到自签证书会报"不受信任的颁发机构",
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# 加 TrustServerCertificate=Yes 即可信任该证书。设为 false 时不影响原有行为。
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if db_cfg.get("trust_server_certificate", False):
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parts.append("TrustServerCertificate=Yes;")
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return "".join(parts)
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def fetch_params_by_ids(
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db_cfg: dict[str, Any], zong_pai_hao_list: list[str]
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) -> dict[str, str | None]:
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"""按总排号批量查询新参数字段。
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返回 dict:{总排号: 新参数文本}。数据库中不存在的总排号,其值为 None
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(而不是直接从结果里省略该 key),方便调用方区分"没查到"和"查到但内容为空"。
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一个总排号只对应一条记录(业务已确认为一对一关系);如果实际数据出现
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重复总排号,取查询结果的第一条并记录一条 WARNING 日志,不中断整体流程。
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"""
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if not zong_pai_hao_list:
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return {}
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result: dict[str, str | None] = {zph: None for zph in zong_pai_hao_list}
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schema = db_cfg["schema"]
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table = db_cfg["table"]
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id_col = db_cfg["id_column"]
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param_col = db_cfg["param_column"]
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# 表名必须带 schema 前缀(如 [dbo].[表名]),只写表名在 schema 不是默认dbo时
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# 会查到错误的表,甚至直接报"找不到对象"。schema 和表名分别加中括号转义,
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# 不能写成 [schema.table],那样会被当成一个整体标识符解析。
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qualified_table = f"[{schema}].[{table}]"
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# 用参数化查询防止总排号里混入特殊字符导致 SQL 注入或语法错误
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placeholders = ",".join("?" for _ in zong_pai_hao_list)
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sql = f"SELECT [{id_col}], [{param_col}] FROM {qualified_table} WHERE [{id_col}] IN ({placeholders})"
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conn_str = _build_conn_str(db_cfg)
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try:
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with pyodbc.connect(conn_str, timeout=db_cfg["connect_timeout"]) as conn:
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cursor = conn.cursor()
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# 查询超时设在 Connection 上(pyodbc 的 timeout 是 Connection 属性,
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# Cursor 没有该属性,设 cursor.timeout 会报 AttributeError)。
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conn.timeout = db_cfg["query_timeout"]
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cursor.execute(sql, zong_pai_hao_list)
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seen = set()
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for row in cursor.fetchall():
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zph, param = row[0], row[1]
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if zph in seen:
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logger.warning("总排号 %s 存在重复记录,已取第一条", zph)
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continue
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seen.add(zph)
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result[zph] = param
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except pyodbc.Error as e:
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raise DatabaseError(f"数据库查询失败: {e}") from e
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return result
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def fetch_param_by_id(db_cfg: dict[str, Any], zong_pai_hao: str) -> str | None:
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"""单个总排号查询的便捷封装。"""
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return fetch_params_by_ids(db_cfg, [zong_pai_hao]).get(zong_pai_hao)
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