問題描述

問題描述： 最近在玩node.js連接mysql數(shù)據(jù)庫(kù)，也連接成功，可以增刪改了。但是有一個(gè)問題，每當(dāng)拋出異常時(shí)，我的程序自動(dòng)停止？？？并且報(bào)以下錯(cuò)誤：

events.js:160 throw er; // Unhandled ’error’ event ^Error: Connection lost: The server closed the connection. at Protocol.end (D:SoftWareZBJWORKSPACEWebStormWKnode-log-regnode_modulesmysqllibprotocolProtocol.js:109:13) at Socket.<anonymous> (D:SoftWareZBJWORKSPACEWebStormWKnode-log-regnode_modulesmysqllibConnection.js:109:28) at emitNone (events.js:91:20) at Socket.emit (events.js:185:7) at endReadableNT (_stream_readable.js:974:12) at _combinedTickCallback (internal/process/next_tick.js:74:11) at process._tickCallback (internal/process/next_tick.js:98:9)

很奇怪為什么自動(dòng)停止程序？我的連接數(shù)據(jù)庫(kù)程序如下：

var mysql = require(’mysql’);var db_config = { host: ’127.0.0.1’, port:’3306’, user: ’root’, password: ’root’, database: ’test’};function connectServer() { var client = mysql.createConnection(db_config); return client;}function selectFun(client, username, callback) { //console.log('查詢參數(shù)：'+username); //client為一個(gè)mysql連接對(duì)象 client.query(’select * from user where name='’ + username + ’'’, function (err, results, fields) { // console.log('查詢結(jié)果：'+results);if (err) throw err;callback(results); });}function insertFun(client, username, password, callback) { var usr = {name:username,pwd:password}; client.query(’insert into user set ?’, usr, function (err, result) {if (err) { console.log('error:' + err.message); return err;}callback(result); });}exports.connect = connectServer;exports.selectFun = selectFun;exports.insertFun = insertFun;

問題解答

不要在回調(diào)函數(shù)中拋出異常，需要使用nodejs的方式：

callback(e,result,...);回調(diào)函數(shù)的第一個(gè)參數(shù)為Error對(duì)象，如果沒發(fā)生錯(cuò)誤，傳入null