一个函数怎么可以包含多个函数

Question

比如我在 service 里定义了几个函数
getA() // 获取 A 的数据
getB() // 获取 B 的数据

router:
api/ab/a 可以获取 a 的数据
api/ab/b 可以获取 b 的数据

现在想让 api/ab 显示 a 和 b 所有的数据，
是不是我就应该写了一个 getAB() 然后用 getAB() 这个函数获取 a 和 b 所有数据呢？

这个格式怎么写啊？
我现在是这么写的，不过获取老是空。

router

router.get('/classifications', classificationController.index);

controller

/**
 * classification 列表
 */
export const index = async (
    request: Request,
    response: Response,
    next: NextFunction,
) => {

    try {
        const classification = await getClassification();
        response.send(classification);
    } catch (error) {
        next(error);
    }
};

service

import { connection } from '../app/database/mysql';
/**
 * 获取 classification
 */
export const getClassification = async () => {
  const dataArry = {
    category: null,
    grade: null,
    version: null,
    subject: null,
  }

  dataArry.category = getCategory();
  dataArry.grade = getGrade();
  dataArry.version = getVersion();
  dataArry.subject = getSubject();
  return dataArry;
};

/**
 * 获取 category 列表
 */
export const getCategory = async () => {
  const statement = `
     SELECT
       DISTINCT(category)
     FROM post
   `;

  const [data] = await connection.promise().query(statement);

  return data;
};

/**
 * 获取 grade 列表
 */
export const getGrade = async () => {
  const statement =
    `
     SELECT
       DISTINCT(grade)
     FROM post
     ORDER BY FIELD(SUBSTRING(grade,1,1),'一','二','三','四','五','六','七','八','九');
   `;

  const [data] = await connection.promise().query(statement);

  return data;
};

/**
 * 获取 version 列表
 */
export const getVersion = async () => {
  const statement = `
     SELECT
       DISTINCT(version)
     FROM post
   `;

  const [data] = await connection.promise().query(statement);

  return data;
};

/**
 * 获取 subject 列表
 */
export const getSubject = async () => {
  const statement = `
     SELECT
       DISTINCT(subject)
     FROM post
   `;

  const [data] = await connection.promise().query(statement);

  return data;
};

Answer 1

/**
 * classification 列表
 */
export const index = async (
    request: Request,
    response: Response,
    next: NextFunction,
) => {

    try {
        const category = await getCategory();
        const grade = await getGrade();
        const version = await getVersion();
        const subject = await getSubject();

        response.send({
          category,
          grade,
          version,
          subject
       });
    } catch (error) {
        next(error);
    }
};

不用 getClassification ()这个方法，直接这样就解决了