准备

npm install mongodb /*安装mongodb模块*/

一些mongodb命令

show dbs //展示所有数据库
use db //使用该数据库,未创建则直接创建
db.documents.drop() //删除该collection中所有数据(或者使用.remove()通过条件删除)
db.documents.find() //查询该collection中所有数据

连接mongodb

/*app.js*/
var MongoClient = require('mongodb').MongoClient
  , assert = require('assert');
/*assert模块用于编写程序的单元测试用例*/

// Connection URL
var url = 'mongodb://localhost:27017/elys';/*请求url*/
// 通过mongodb提供的connect方法来连接数据库
MongoClient.connect(url, function(err, db) { /*这里的db便是连接成功的mongodb*/
  assert.equal(null, err);/*表达式不符合时输出err*/
  console.log("Connected correctly to server");

  db.close();
});

插入数据

/*新增一个用于插入数据的方法*/
var insertDocuments = function (db, callback){
    var collection = db.collection('documents')/*获取collection*/
    collection.insertMany([/*操作语句*/
        {a:1}, {a:2}, {a:3}/*提供的数据*/
    ], function(err, result){/*回调*/
        assert.equal(err, null)
        assert.equal(3, result.result.n) /*检查结果行为等(是不是真的3个)*/
        assert.equal(3, result.ops.length)
        console.log("Inserted 3 documents into the document collection")
        callback(result) /*返回结果*/
    })
}

/*修改后的app.js*/
//...
console.log("Connected correctly to server");
/*调用该方法*/
  insertDocuments(db, function(){
    db.close();
  })
//...

更新数据

var updateDocument = function (db, callback){
    var collection = db.collection('documents')
    collection.updateOne({ a: 2 },{ $set: {b:1}}, function(err, result){
        /*mongodb提供许多api,updateOne()是其中之一*/
        assert.equal(err, null)
        assert.equal(1, result.result.n)
        console.log("Updated the document with thie field a equal to 2")
        callback(result)
    })
}

/*修改后的app.js*/
//...
console.log("Connected correctly to server");
/*调用该方法*/
 insertDocuments(db, function(){
    updateDocument(db, function(){
        db.close();
    })
  })
//...

删除数据

var deleteDocument = function(db, callback){
    var collection = db.collection('documents')

    collection.deleteOne({a:3}, function(err, result){
        assert.equal(err, null)
        assert.equal(1, result.result.n)
        console.log("Remove the document with the field a equal to 3")
        callback(result)
        //console.log(result)
    })
}

/*修改后的app.js*/
//...
console.log("Connected correctly to server");
/*调用该方法*/
 insertDocuments(db, function(){
    updateDocument(db, function(){
        deleteDocument(db, function(){
            db.close();
        })
    })
  })
//...

查询数据

var findDocuments = function(db, callback){
    var collection = db.collection('documents')

    collection.find({}).toArray(function(err, docs){
        assert.equal(err, null)
        assert.equal(2, docs.length)
        console.log("Found the following records")
        console.dir(docs)
        callback(docs)
    })
}

/*修改后的app.js*/
//...
console.log("Connected correctly to server");
/*调用该方法*/
 insertDocuments(db, function(){
    updateDocument(db, function(){
        deleteDocument(db, function(){
            findDocuments(db, function(){
                db.close();
            })
        })
    })
  })
//...

参考
https://github.com/mongodb/node-mongodb-native

未完待续