var mongoose = require('mongoose');

mongoose.connect('mongodb://127.0.0.1:27017/whhhh', { useMongoClient: true });

var db = mongoose.connection;

db.on('error', console.error.bind(console, 'connection error:'));

db.once('open', function (callback) {

    console.log("数据库成功连接");

});

module.exports = db;

var mongoose = require('mongoose');

var db = require("./db.js");

  var   Schema=mongoose.Schema;

var UserSchema = new mongoose.Schema({

    username:{type:String},

    usersex:{type:String},

    userage:{type:Number}

});

module.exports = mongoose.model('User',UserSchema);

var User = require("./user.js");

function update(){

    var wherestr = {'username' : 'zhangming'};

    var updatestr = {'userage': ''};

    User.update(wherestr, updatestr, function(err, res){

        if (err) {

            console.log("Error:" + err);

        }

        else {

            console.log("Res:" + res);

        }

    })

}

update();

var User = require("./user.js");

function findByIdAndUpdate() {

    var id='59fa714f16ee5b557824b8e5';

    var updatestr={'usersex':'nu'};

    User.findByIdAndUpdate (id,updatestr,function(err,res)

    {

        if (err) {

            console.log("Error:" + err);

        }

        else {

            console.log("Res:" + res);

        }

    }

)

}

findByIdAndUpdate();