from typing import Annotated, Any from langchain.tools import tool from pydantic import BaseModel, Field from src.utils import logger from .connection import ( MySQLConnectionManager, QueryTimeoutError, execute_query_with_timeout, limit_result_size, ) from .exceptions import MySQLConnectionError from .security import MySQLSecurityChecker # 全局连接管理器实例 _connection_manager: MySQLConnectionManager | None = None def get_connection_manager() -> MySQLConnectionManager: """获取全局连接管理器""" global _connection_manager if _connection_manager is None: import os # 从环境变量中读取 MySQL 配置 mysql_config = { "host": os.getenv("MYSQL_HOST"), "user": os.getenv("MYSQL_USER"), "password": os.getenv("MYSQL_PASSWORD"), "database": os.getenv("MYSQL_DATABASE"), "port": int(os.getenv("MYSQL_PORT", "3306")), "charset": "utf8mb4", "description": os.getenv("MYSQL_DATABASE_DESCRIPTION", "默认 MySQL 数据库"), } # 验证配置完整性 required_keys = ["host", "user", "password", "database"] for key in required_keys: if not mysql_config[key]: raise MySQLConnectionError(f"MySQL configuration missing required key: {key}") _connection_manager = MySQLConnectionManager(mysql_config) return _connection_manager class TableListModel(BaseModel): """获取表名列表的参数模型""" pass @tool(name_or_callable="查询表名及说明", args_schema=TableListModel) def mysql_list_tables() -> str: """获取数据库中的所有表名 这个工具用来列出当前数据库中所有的表名，帮助你了解数据库的结构。 """ try: conn_manager = get_connection_manager() with conn_manager.get_cursor() as cursor: # 获取表名 cursor.execute("SHOW TABLES") logger.debug("Executed `SHOW TABLES` query") tables = cursor.fetchall() if not tables: return "数据库中没有找到任何表" # 提取表名 table_names = [] for table in tables: table_name = list(table.values())[0] table_names.append(table_name) # 获取每个表的行数信息 # table_info = [] # for table_name in table_names: # try: # cursor.execute(f"SELECT COUNT(*) as count FROM `{table_name}`") # logger.debug(f"Executed `SELECT COUNT(*) FROM {table_name}` query") # count_result = cursor.fetchone() # row_count = count_result["count"] # table_info.append(f"- {table_name} (约 {row_count} 行)") # except Exception: # table_info.append(f"- {table_name} (无法获取行数)") all_table_names = "\n".join(table_names) result = f"数据库中的表:\n{all_table_names}" if db_note := conn_manager.config.get('description'): result = f"数据库说明: {db_note}\n\n" + result logger.info(f"Retrieved {len(table_names)} tables from database") return result except Exception as e: error_msg = f"获取表名失败: {str(e)}" logger.error(error_msg) return error_msg class TableDescribeModel(BaseModel): """获取表结构的参数模型""" table_name: str = Field(description="要查询的表名", example="users") @tool(name_or_callable="描述表", args_schema=TableDescribeModel) def mysql_describe_table(table_name: Annotated[str, "要查询结构的表名"]) -> str: """获取指定表的详细结构信息 这个工具用来查看表的字段信息、数据类型、是否允许NULL、默认值、键类型等。 帮助你了解表的结构，以便编写正确的SQL查询。 """ try: # 验证表名安全性 if not MySQLSecurityChecker.validate_table_name(table_name): return "表名包含非法字符，请检查表名" conn_manager = get_connection_manager() with conn_manager.get_cursor() as cursor: # 获取表结构 cursor.execute(f"DESCRIBE `{table_name}`") columns = cursor.fetchall() if not columns: return f"表 {table_name} 不存在或没有字段" # 获取字段备注信息 column_comments: dict[str, str] = {} try: cursor.execute( """ SELECT COLUMN_NAME, COLUMN_COMMENT FROM information_schema.COLUMNS WHERE TABLE_NAME = %s AND TABLE_SCHEMA = %s """, (table_name, conn_manager.database_name), ) comment_rows = cursor.fetchall() for row in comment_rows: column_name = row.get("COLUMN_NAME") if column_name: column_comments[column_name] = row.get("COLUMN_COMMENT") or "" except Exception as e: logger.warning(f"Failed to fetch column comments for table {table_name}: {e}") # 格式化输出 result = f"表 `{table_name}` 的结构:\n\n" result += "字段名\t\t类型\t\tNULL\t键\t默认值\t\t额外\t备注\n" result += "-" * 80 + "\n" for col in columns: field = col["Field"] or "" type_str = col["Type"] or "" null_str = col["Null"] or "" key_str = col["Key"] or "" default_str = col.get("Default") or "" extra_str = col.get("Extra") or "" comment_str = column_comments.get(field, "") # 格式化输出 result += ( f"{field:<16}\t{type_str:<16}\t{null_str:<8}\t{key_str:<4}\t" f"{default_str:<16}\t{extra_str:<16}\t{comment_str}\n" ) # 获取索引信息 try: cursor.execute(f"SHOW INDEX FROM `{table_name}`") indexes = cursor.fetchall() if indexes: result += "\n索引信息:\n" index_dict = {} for idx in indexes: key_name = idx["Key_name"] if key_name not in index_dict: index_dict[key_name] = [] index_dict[key_name].append(idx["Column_name"]) for key_name, columns in index_dict.items(): result += f"- {key_name}: {', '.join(columns)}\n" except Exception as e: logger.warning(f"Failed to get index info for table {table_name}: {e}") logger.info(f"Retrieved structure for table {table_name}") return result except Exception as e: error_msg = f"获取表 {table_name} 结构失败: {str(e)}" logger.error(error_msg) return error_msg class QueryModel(BaseModel): """执行SQL查询的参数模型""" sql: str = Field(description="要执行的SQL查询语句（只能是SELECT语句）", example="SELECT * FROM users WHERE id = 1") timeout: int | None = Field(default=60, description="查询超时时间（秒），默认60秒，最大600秒", ge=1, le=600) @tool(name_or_callable="执行 SQL 查询", args_schema=QueryModel) def mysql_query( sql: Annotated[str, "要执行的SQL查询语句（只能是SELECT语句）"], timeout: Annotated[int | None, "查询超时时间（秒），默认60秒，最大600秒"] = 60, ) -> str: """执行只读的SQL查询语句 这个工具用来执行SQL查询并返回结果。支持复杂的SELECT查询，包括JOIN、GROUP BY等。 注意：只能执行查询操作，不能修改数据。 参数: - sql: SQL查询语句 - timeout: 查询超时时间（防止长时间运行的查询） """ try: # 验证SQL安全性 if not MySQLSecurityChecker.validate_sql(sql): return "SQL语句包含不安全的操作或可能的注入攻击，请检查SQL语句" if not MySQLSecurityChecker.validate_timeout(timeout): return "timeout参数必须在1-600之间" conn_manager = get_connection_manager() connection = conn_manager.get_connection() effective_timeout = timeout or 60 try: result = execute_query_with_timeout(connection, sql, timeout=effective_timeout) except QueryTimeoutError as timeout_error: logger.error(f"MySQL query timed out after {effective_timeout} seconds: {timeout_error}") raise except Exception: conn_manager.invalidate_connection() raise if not result: return "查询执行成功，但没有返回任何结果" # 限制结果大小 limited_result = limit_result_size(result, max_chars=10000) # 检查结果是否被截断 if len(limited_result) < len(result): warning = f"\n\n⚠️ 警告: 查询结果过大，只显示了前 {len(limited_result)} 行（共 {len(result)} 行）。\n" warning += "建议使用更精确的查询条件或使用LIMIT子句来减少返回的数据量。" else: warning = "" # 格式化输出 if limited_result: # 获取列名 columns = list(limited_result[0].keys()) # 计算每列的最大宽度 col_widths = {} for col in columns: col_widths[col] = max(len(str(col)), max(len(str(row.get(col, ""))) for row in limited_result)) col_widths[col] = min(col_widths[col], 50) # 限制最大宽度 # 构建表头 header = "| " + " | ".join(f"{col:<{col_widths[col]}}" for col in columns) + " |" separator = "|" + "|".join("-" * (col_widths[col] + 2) for col in columns) + "|" # 构建数据行 rows = [] for row in limited_result: row_str = "| " + " | ".join(f"{str(row.get(col, '')):<{col_widths[col]}}" for col in columns) + " |" rows.append(row_str) result_str = f"查询结果（共 {len(limited_result)} 行）:\n\n" result_str += header + "\n" + separator + "\n" result_str += "\n".join(rows[:50]) # 最多显示50行 if len(rows) > 50: result_str += f"\n\n... 还有 {len(rows) - 50} 行未显示 ..." result_str += warning logger.info(f"Query executed successfully, returned {len(limited_result)} rows") return result_str return "查询执行成功，但返回数据为空" except Exception as e: error_msg = f"SQL查询执行失败: {str(e)}\n\n{sql}" # 提供更有用的错误信息 if "timeout" in str(e).lower(): error_msg += "\n\n💡 建议：查询超时了，请尝试以下方法：\n" error_msg += "1. 减少查询的数据量（使用WHERE条件过滤）\n" error_msg += "2. 使用LIMIT子句限制返回行数\n" error_msg += "3. 增加timeout参数值（最大600秒）" elif "table" in str(e).lower() and "doesn't exist" in str(e).lower(): error_msg += "\n\n💡 建议：表不存在，请使用 mysql_list_tables 查看可用的表名" elif "column" in str(e).lower() and "doesn't exist" in str(e).lower(): error_msg += "\n\n💡 建议：列不存在，请使用 mysql_describe_table 查看表结构" elif "not enough arguments for format string" in str(e).lower(): error_msg += ( "\n\n💡 建议：SQL 中的百分号 (%) 被当作参数占位符使用。" " 如需匹配包含百分号的文本，请将百分号写成双百分号 (%%) 或使用参数化查询。" ) logger.error(error_msg) return error_msg def get_mysql_tools() -> list[Any]: """获取MySQL工具列表""" return [mysql_list_tables, mysql_describe_table, mysql_query]