刚开始直接使用ctx.body直接赋值的方式，发现直接GG了，找了资料才发现不能直接操作

const fs = require('fs');
const router = require('koa-router')();
const mysql = require('mysql');
const config = require('../config');
const connection = mysql.createConnection(config.db_set);

connection.connect(function (err) {
  if (err) {
     console.log(err)
  }
});

var getInformations = 'select * from v_position'; 

router.get('/getInformations', async (ctx, next) => {
  await next();
  ctx.body = result;
})

而是需要使用promise封装才可以

router.get('/getInformations', async (ctx, next) => {
 let query = ()=>{
   return new Promise((resolve,reject)=>{
       connection.query(getInformations,(err,data) => {
           if(err){
               resolve({
                   message:err.message
               })
           }
            resolve(data);
       })
   })
}
let result = await query();
  ctx.body = result;
})