这段代码运行后，也不报错，也不输出，真的让人抓瞎呀，请教！

const query = require('./mysql.js');
const Koa = require('koa');
const async = require('async');
const app = new Koa();

app.use(async (ctx, next) => {
     ctx.execSql = query;
     await next();
   });

async (ctx) => {
    try {
      let result = await ctx.execSql(`select * from contact_user where phone = 1 and password = 1`);
      if (result.length > 0) {
        console.log('a');
      } else {
        console.log('b');
      }
    } catch (err) {
      console.log('c');
    }
  }

也不报错，也不输出，真的让人抓瞎呀！！！