本文实例讲述了Node.js中SQLite3和MongoDB的用法。分享给大家供大家参考，具体如下：

setup.js：初始化数据库

var util = require('util');var async = require('async'); //npm install asyncvar notesdb = require('./nodesdb-sqlite3');// var notesdb = require('./notesdb-mongoose');notesdb.connect(function(error){ if (error) throw error;});notesdb.setup(function(error){ if (error){ util.log('ERROR ' + error); throw error; } async.series([ //async.series函数可以控制函数按顺序执行，从而保证最后的函数在所有其他函数完成之后执行 function(cb){ notesdb.add("test", "testtest", function(error){ if (error) util.log('ERROR ' + error); cb(error); }); } ], function(error, results){ if (error) util.log('ERROR ' + error); notesdb.disconnect(function(err){}); } );});

nodesdb-sqlite3.js

SQLite3 是一个轻量级的进程内SQL引擎

它是一个无服务器且无需配置的SQL数据库引擎，仅仅是作为一个独立的库被链接到应用程序上

npm install sqlite3 安装此模块之前先在系统上安装sqlite3库 http://www.sqlite.org/download.html 下载

//数据库接口库var util = require('util');var sqlite3 = require('sqlite3');sqlite3.verbose();var db = undefined;exports.connect = function(callback){ db = new sqlite3.Database("chap06.sqlite3", sqlite3.OPEN_READWRITE | sqlite3.OPEN_CREATE, function(err){ if (err){ util.log('FAIL on creating database ' + err); callback(err); } else { callback(null); } });}//此处的disconnect函数是空的exports.disconnect = function(callback){ callback(null);}exports.setup = function(callback){ db.run("CREATE TABLE IF NOT EXISTS notes " + "(ts DATETIME, author VARCHAR(255), note TEXT)", function(err){ if (err){ util.log('FAIL on creating table ' + err); callback(err); } else { callback(null); } });}exports.emptyNote = {"ts": "", author: "", note: ""};exports.add = function(author, note, callback){ db.run("INSERT INTO notes (ts, author, note) " + "VALUES (?, ?, ?);", [new Date(), author, note], function(error){ if (error){ util.log('FAIL on add ' + error); callback(error); } else { callback(null); } });}exports.delete = function(ts, callback){ db.run("DELETE FROM notes WHERE ts = ?;", [ts], function(err){ if (err){ util.log('FAIL to delete ' + err); callback(err); } else { callback(null); } });}exports.edit = function(ts, author, note, callback){ db.run("UPDATE notes " + "SET ts = ?, author = ?, note = ? " + "WHERE ts = ?", [ts, author, note, ts], function(err){ if (err){ util.log('FAIL on updating table ' + err); callback(err); } else { callback(null); } });}exports.allNotes = function(callback){ util.log(' in allnote'); db.all("SELECT * FROM notes", callback);}exports.forAll = function(doEach, done){ db.each("SELECT * FROM notes", function(err, row){ if (err){ util.log('FAIL to retrieve row ' + err); done(err, null); } else { doEach(null, row); } }, done);}exports.findNoteById = function(ts, callback){ var didOne = false; db.each("SELECT * FROM notes WHERE ts = ?", [ts], function(err, row){ if (err){ util.log('FAIL to retrieve row ' + err); callback(err, null); } else { if (!didOne){ callback(null, row); didOne = true; //保证回调函数只被执行一次 } } });}

notesdb-mongoose.js

MongoDB是nosql数据库的领头羊之一，"可扩展、高性能、开源、面向文档的数据库"，它使用JSON风格的文档。

Mongoose是用于访问MongoDB的模块之一，它是一个对象建模工具，意味着你的程序负责定义模式对象来描述数据，

而Mongoose负责数据到MongoDB的存储。

Mongoose对于Node和MongoDB而言是一个非常强大的对象建模工具，使用嵌入式文档，是一个类型灵活的系统，

适用于字段输入、字段验证、虚拟字段等。

MongoDB在Windows下安装部署 ：

安装Mongoose模块

npm install mongoose

Mongoose不是唯一一个在node中使用MongoDB的工具。

var util = require('util');var mongoose = require('mongoose');var Schema = mongoose.Schema;var dburl = 'mongodb://localhost/chap06'; //dburl用于连接已运行的MongoDBexports.connect = function(callback){ mongoose.connect(dburl);}exports.disconnect = function(callback){ mongoose.disconnect(callback);}exports.setup = function(callback){callback(null);}//定义模式var NoteSchema = new Schema({ ts: {type: Date, default: Date.now}, //默认值 author: String, note: String});//将NoteSchema作为Mongoose的模型注册进去mongoose.model('Note', NoteSchema);var Note = mongoose.model('Note');exports.emptyNote = {"_id": "", author: "", note: ""};exports.add = function(author, note, callback){ var newNote = new Note(); newNote.author = author; newNote.note = note; newNote.save(function(err){ if (err){ util.log('FATAL ' + err); callback(err); } else { callback(null); } });}exports.delete = function(id, callback){ exports.findNoteById(id, function(err, doc){ if (err){ callback(err); } else { util.log(util.inspect(doc)); doc.remove(); callback(null); } });}exports.edit = function(id, author, note, callback){ exports.findNoteById(id, function(err, doc){ if (err){ callback(err); } else { doc.ts = new Date(); doc.author = author; doc.note = note; doc.save(function(err){ if (err){ util.log('FATAL ' + err); callback(err); } else { callback(null); } }); } });}exports.allNotes = function(callback){ Note.find({}, callback);}exports.forAll = function(doEach, done){ Note.find({}, function(err, docs){ if (err){ util.log('FATAL ' + err); done(err, null); } docs.forEach(function(doc){ doEach(null, doc); }); done(null); });}var findNoteById = exports.findNoteById = function(id, callback){ Note.findOne({_id: id}, function(err, doc){ if (err){ util.log('FATAL ' + err); callback(err, null); } callback(null, doc); });}

app.js

//在数据库需要放置在一台计算机上时，应该考虑使用SQLite3//控制器，在nodesdb-sqlite3.js和notesdb-mongoose.js模块之间切换var util = require('util');var url = require('url');var express = require('express');var nmDbEngine = 'sqlite3'; //用于命名数据库引擎、选择合适的notesdb实现和选择合适的views目录//var nmDbEngine = 'mongoose';var notesdb = require('./nodesdb-' + nmDbEngine);var app = express();app.use(express.logger());app.use(express.cookieParser()); //添加cookieParser中间件app.use(express.bodyParser());app.engine('.html', require('ejs').__express); //3.X//app.register('.html', require('ejs')); //2.Xapp.set('views', __dirname + '/views-' + nmDbEngine);app.set('view engine', 'ejs');//是一个路由中间件函数，用于在一些路由器函数中解析URL查询参数var parseUrlParams = function(req, res, next){ req.urlP = url.parse(req.url, true); next();}//检查用户是否被允许访问，这里只检查cookie是否等于AOK，这个单词通常意味着一切都没问题var checkAccess = function(req, res, next){ if (!req.cookies || !req.cookies.notesaccess || req.cookies.notesaccess !== "AOK"){ res.redirect('/login'); } else { next(); }}notesdb.connect(function(error){ if (error) throw error;})app.on('close', function(error){ notesdb.disconnect(function(err){});});app.get('/', function(req, res) {res.redirect('/view');});app.get('/view', checkAccess, function(req, res){ //可以在每个路由上加checkAccess检查 notesdb.allNotes(function(err, notes){ if (err){ util.log('ERROR ' + err); throw err; } else { res.render('viewnotes.html', {title: "Notes ("+ nmDbEngine +")", notes: notes}); } });});app.get('/add', function(req, res){ res.render('addedit.html', {title: "Notes ("+ nmDbEngine +")", postpath: '/add', note: notesdb.emptyNote});});app.post('/add', function(req, res){ notesdb.add(req.body.author, req.body.note, function(error){ if (error) throw error; res.redirect('/view'); });});app.get('/del', parseUrlParams, function(req, res){ notesdb.delete(req.urlP.query.id, function(error){ if (error) throw error; res.redirect('/view'); });});app.get('/edit', parseUrlParams, function(req, res){ notesdb.findNoteById(req.urlP.query.id, function(error, note){ if (error) throw error; res.render('addedit.html', {title: "Notes ("+ nmDbEngine +")", postpath: '/edit', note: note}); });});app.post('/edit', function(req, res){ notesdb.edit(req.body.id, req.body.author, req.body.note, function(error){ if (error) throw error; res.redirect('/view'); });});app.get('/login', function(req, res){ res.render('login.html', {title: "Notes LOGIN ("+ nmDbEngine +")"});});app.post('/login', function(req, res){ //此处可以添加检查用户信息的逻辑 //... res.cookie('notesaccess', 'AOK'); res.redirect('/view');});app.listen(3000);

show.js

//控制台显示var util = require('util');var notesdb = require('./notesdb-sqlite3');// var notesdb = require('./notesdb-mongoose');notesdb.connect(function(error){ if (error) throw error;});notesdb.forAll(function(error, row){ util.log('ROW: ' + util.inspect(row));}, function(error){ if (error) throw error; util.log('ALL DONE'); notesdb.disconnect(function(err){});});

前台页面在views-sqlite3目录下

layout.html

<!DOCTYPE html><html><head> <title><%= title%></title></head><body> <h1><%= title%></h1> <p><a href='/view'>View</a> | <a href='/add'>Add</a></p></body></html>

viewnotes.html

<% include layout.html %><table><% notes.forEach(function(note){ %> <tr> <td> <p><%=new Date(note.ts).toString()%>: by <b><%=note.author%></b></p> <p><%=note.note%></p> </td> <td> <form method="get" action="/del"> <input type="submit" value="Delete" /> <input type="hidden" name="id" value="<%=note.ts%>" /> </form> <br/> <form method="get" action="/edit"> <input type="submit" value="Edit" /> <input type="hidden" name="id" value="<%=note.ts%>" /> </form> </td> </tr> <% }); %></table>

addedit.html

<% include layout.html %><form method="post" action="<%=postpath%>"> <% if (note){ %> <input type="hidden" name="id" value="<%=note.ts%>" /> <% } %> <input type="text" name="author" value="<%=note.author%>" /> <br/> <textarea rows="5" cols="40" name="note"> <%=note.note%> </textarea> <br/> <input type="submit" value="Submit" /></form>

login.html

<% include layout.html %><form method="POST" action="/login"> <p>Click the <i>Login</i> to log in.</p> <input type="submit" value="Login" /></form>

node setup.js

node app.js

希望本文所述对大家nodejs程序设计有所帮助。