07.node+express+mongodb 简单整合

1.创建db.js

var mongodb = require("mongodb");var MongoClient = mongodb.MongoClient;function _connect(callback){    var url = "mongodb://localhost:27017/company";    MongoClient.connect(url,function(err,db){        callback(err,db);        db.close();    })}exports.find = function(collectionName,json,callback){    _connect(function(err,db){        db.collection(collectionName).find(query).toArray(function(err,results){            callback(err,results);        });    })}exports.insert = function(collectionName,json,callback){    _connect(function(err,db){        db.collection(collectionName).insertOne(json,function(err,results){            callback(err,results);        })    });}

2.创建请求js

var test = require("./module/db.js");var express = require("express");var app = express();app.get("/",function(req,res){    test.find("worker",{"name":"李东方"},function(err,results){        res.json(results);    });});app.listen(80);

如果不太懂callback的话，请看下面小例子或度娘

这段并不会输出12

function test(){    function a (){        return 12;    }    a();}console.log(test());

这段会输出12

function test(callback){    function a(){        callback(13);    }    a();}test(function(num){    console.log(num);});