MySQL MCP Server

Instructions

Implementation Reference

• src/index.ts:426-476 (handler)

  Implements the core logic for the 'delete_data' tool: validates input arguments, checks if the SQL query starts with 'DELETE FROM', executes the query on the MySQL connection pool, logs the transaction, handles errors, and returns a structured success or error response.

  private async handleDeleteData(request: any, transactionId: string) {
    if (!isValidSqlQueryArgs(request.params.arguments)) {
      throw new McpError(
        ErrorCode.InvalidParams,
        'SQL 查询参数无效。'
      );
    }
  
    const query = request.params.arguments.query;
  
    if (!isDeleteQuery(query)) {
      throw new McpError(
        ErrorCode.InvalidParams,
        'delete_data 工具仅允许 DELETE FROM 查询。'
      );
    }
  
    console.error(`[${transactionId}] 执行 DELETE 查询: ${query}`);
  
    try {
      const [result] = await this.pool.query(query);
      console.error(`[${transactionId}] 数据删除成功`);
  
      return {
        content: [
          {
            type: 'text',
            text: JSON.stringify({
              success: true,
              message: '数据删除成功',
              result
            }, null, 2),
          },
        ],
      };
    } catch (error) {
      console.error(`[${transactionId}] 查询出错:`, error);
      if (error instanceof Error) {
        return {
          content: [
            {
              type: 'text',
              text: `MySQL 错误: ${error.message}`,
            },
          ],
          isError: true,
        };
      }
      throw error;
    }
  }

• src/index.ts:158-171 (schema)

  Defines the metadata (name, description) and input schema (object with required 'query' string field) for the 'delete_data' tool, returned in response to list_tools requests.

  {
    name: 'delete_data',
    description: '从 MySQL 数据库表中删除数据',
    inputSchema: {
      type: 'object',
      properties: {
        query: {
          type: 'string',
          description: '要执行的 SQL DELETE FROM 语句',
        },
      },
      required: ['query'],
    },
  },

• src/index.ts:204-205 (registration)

  Registers the dispatching of 'delete_data' tool calls to the specific handleDeleteData handler function within the CallToolRequestSchema request handler switch statement.

  case 'delete_data':
    return this.handleDeleteData(request, transactionId);

• src/index.ts:48-49 (helper)

  Helper function specifically used by the delete_data handler to validate that the provided SQL query is a DELETE FROM statement.

  const isDeleteQuery = (query: string): boolean =>
    query.trim().toLowerCase().startsWith('delete from');