第一个简单的例子

var mongoose = require('mongoose');

var db = mongoose.createConnection('mongodb://127.0.0.1:27017');

db.once('open',function(callback){
  console.log('数据库成功连接');
})

module.exports = db;

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <title>Document</title>
</head>
<body>
  <form action="/doadd" method="get">
    <p>书名：<input type="text" name="name" /></p>
    <p>作者：<input type="text" name="author" /></p>
    <p>价格：<input type="text" name="price"></p>
    <p><input type="submit"></p>
  </form>
</body>
</html>

<!-- index.ejs -->
<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <title>Document</title>
  <style>
  table,tr,td{
    border:1px solid red;
  }
  </style>
</head>
<body>
<a href="/addbook">增加图书</a>
  <table>
    <tr>
      <td>oid</td>
      <td>图书名字</td>
      <td>作者</td>
      <td>价格</td>
      <td>操作</td>
    </tr>
    <% for(var i = 0;i < tushu.length; I==){%>
    <tr>
      <td><%=tushu[i]._id%></td>
      <td><%=tushu[i].name%></td>
      <td><%=tushu[i].author%></td>
      <td><%=tushu[i].price%></td>
      <td><a href="/edit?id<%=tushu[i]._id%>"></a></td>
    </tr>
    <%=tushu[i].price%>
  </table>
</body>
</html>

//app.js
var express = require('express');
var app = express();


app.set('view engine','ejs');

app.get('/addbook',router.addbook);
app.get('/doadd',router.doadd);
app.get('/edit',router.edit);

app.listen(3000);

//book.js
var mongoose = require('mongoose');
var db = require('./db.js');
var ObjectId = require('mongodb').ObjectId();

var bookSchema = new mongoose.Schema({
  name:{type:String},
  autor:{type:String},
  price:{type:Number},
  type:{type:Array}
});

bookSchema.statics.liechusuoyoushu = function(callback){
  this.model('Book').find({},callback);
}
bookSchema.statics.findBookById = function(id,callback){
  this.model('Book').find({'_id':new ObjectId(id)},callback);
}

var bookModel = db.model('Book',bookSchema);

module.exports = bookModel;

var Book = require('../models/Book.js');

exports.showIndex = function(req,res,next){
  Book.liechusuoyoushu(function(err,result){
    res.render('index',{
      'tushu' : result
    });
  });
}
export.addbook = function(req,res,next){
  res.render('addbook');
}

exports.doadd = function(req,res,next){
  Book.create(req.query,function(err){
    if(err){
      res.send('失败');
    }
    res.send('保存成功');
  })
}

exports.edit = function(req,res,next){
  Book.findBookById(req.query.id,function(err,result){
    res.render('edit',result[0]);
  });
}

exports.doedit = function(req,res,next){
  Book.update(req.query.name,function(err,result){
    res.render('edit',result[0]);
  })
}