TypeError: Router.use() requires a middleware function but got a Object-蒲公英云

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

Bertha 。 2021-12-15 06:27 373阅读 0赞

1、错误描述

C:\Users\Administrator.USER-0GUONPPBHK>cd G:\HBuilderXWork\Vue\server
C:\Users\Administrator.USER-0GUONPPBHK>g:
G:\HBuilderXWork\Vue\server>node index
G:\HBuilderXWork\Vue\node_modules\express\lib\router\index.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:\HBuilderXWork\Vue\node_modules\express\lib\router\index.
js:458:13)
    at Function.<anonymous> (G:\HBuilderXWork\Vue\node_modules\express\lib\appli
cation.js:220:21)
    at Array.forEach (<anonymous>)
    at Function.use (G:\HBuilderXWork\Vue\node_modules\express\lib\application.j
s:217:7)
    at Object.<anonymous> (G:\HBuilderXWork\Vue\server\index.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:\HBuilderXWork\Vue\server>

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;