query

Implementation Reference

• database.js:232-253 (handler)

  Handler function for the 'query' tool. Destructures input params, prepares query options, executes queryDatabase helper, and returns MCP-formatted content or error response.

  async function handleQueryTool(params, dbUrl) {
    const { collection, where, field, orderBy, limit, skip } = params;
  
    try {
      const options = {
        field: field || undefined,
        orderBy: orderBy || undefined,
        limit: limit || undefined,
        skip: skip || undefined,
      };
  
      const data = await queryDatabase(collection, where, options, dbUrl);
      return {
        content: [{ type: 'text', text: JSON.stringify(data, null, 2) }],
      };
    } catch (error) {
      return {
        content: [{ type: 'text', text: error.message }],
        isError: true,
      };
    }
  }

• database.js:376-389 (schema)

  Input schema for the 'query' tool defined using Zod, validating parameters: collection (string), where (record), field (optional record), orderBy (optional object), limit/skip (optional numbers).

    collection: z.string().describe('集合名称'),
    where: z.record(z.any()).describe('查询条件 (JQL格式)'),
    field: z.record(z.any()).optional().describe('返回字段 (可选)'),
    orderBy: z
      .object({
        field: z.string(),
        order: z.enum(['asc', 'desc']),
      })
      .optional()
      .describe('排序条件 (可选)'),
    limit: z.number().optional().describe('限制返回数量 (可选)'),
    skip: z.number().optional().describe('跳过记录数 (可选)'),
  },
  handler: (params) => handleQueryTool(params, dbServiceUrl),

• index.js:38-42 (registration)

  Registration of the 'query' tool on the MCP server instance via server.tool(name, paramsSchema, handler).

  server.tool(
    tools.queryTool.name,
    tools.queryTool.params,
    tools.queryTool.handler
  );

• database.js:30-79 (helper)

  Helper function that sends HTTP POST request to the database service endpoint with 'query' action and parameters, handling timeout and response parsing.

  async function queryDatabase(
    collection,
    where,
    options = {},
    dbUrl = DEFAULT_DB_URL
  ) {
    try {
      // 创建请求控制器，用于超时处理
      const controller = new AbortController();
      const timeoutId = setTimeout(() => controller.abort(), REQUEST_TIMEOUT);
  
      // 使用传入的dbUrl或默认URL
      const targetUrl = dbUrl || DEFAULT_DB_URL;
      // console.log('查询操作使用URL:', targetUrl);
  
      // 发送请求
      const response = await fetch(targetUrl, {
        method: 'POST',
        headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify({
          operation: {
            collection,
            action: 'query',
            where,
            field: options.field,
            orderBy: options.orderBy,
            limit: options.limit,
            skip: options.skip,
          },
        }),
        signal: controller.signal,
      });
  
      clearTimeout(timeoutId);
      const result = await response.json();
  
      // 处理响应结果
      if (result.code !== 0) {
        throw new Error(result.msg || '查询失败');
      }
  
      return result.data;
    } catch (error) {
      // 超时错误特殊处理
      if (error.name === 'AbortError') {
        throw new Error(`查询超时: 请求超过${REQUEST_TIMEOUT}毫秒`);
      }
      throw new Error(`查询错误: ${error.message}`);
    }
  }