TypeError: Router.use() requires a middleware function but got a Object

1、错误描述

C:UsersAdministrator.USER-0GUONPPBHK>cd G:HBuilderXWorkVueserver

C:UsersAdministrator.USER-0GUONPPBHK>g:

G:HBuilderXWorkVueserver>node index
G:HBuilderXWorkVue
ode_modulesexpresslib
outerindex.js:458
      throw new TypeError('Router.use() requires a middleware function but got a
 ' + gettype(fn))
      ^

TypeError: Router.use() requires a middleware function but got a Object
    at Function.use (G:HBuilderXWorkVue
ode_modulesexpresslib
outerindex.
js:458:13)
    at Function.<anonymous> (G:HBuilderXWorkVue
ode_modulesexpresslibappli
cation.js:220:21)
    at Array.forEach (<anonymous>)
    at Function.use (G:HBuilderXWorkVue
ode_modulesexpresslibapplication.j
s:217:7)
    at Object.<anonymous> (G:HBuilderXWorkVueserverindex.js:11:5)
    at Module._compile (internal/modules/cjs/loader.js:721:30)
    at Object.Module._extensions..js (internal/modules/cjs/loader.js:732:10)
    at Module.load (internal/modules/cjs/loader.js:620:32)
    at tryModuleLoad (internal/modules/cjs/loader.js:560:12)
    at Function.Module._load (internal/modules/cjs/loader.js:552:3)

G:HBuilderXWorkVueserver>

2、错误原因

     在定义访问数据库，并进行数据操作，没有使用module.exports

3、解决办法

const express = require('express')
const mysql = require('mysql')
const dbConfig = require('./db')
const sqlMap = require('./sqlMap')

var router = express.Router();


var conn = mysql.createConnection(dbConfig.mysql);
conn.connect();

var jsonWrite = function(res,req){
	if(typeof req === 'undefined'){
		res.json({
			code: '1',
			msg: '操作失败'
		});
	}else{
		res.json(req);
	}
}

router.post('/queryData',(res,req) => {
	var sql = sqlMap.stu.select();
	conn.query(sql, function(err,result){
		if(err){
			console.log(err);
		}
		if(result){
			jsonWrite(res,result);
		}
	})
});

module.exports = router;