其實(shí)對(duì)于做一些常見(jiàn)的應(yīng)用拍鲤，增刪改查也就夠用了贴谎，數(shù)據(jù)庫(kù)的東西博大精深，不可一日耳語(yǔ)季稳，當(dāng)然擅这，我這是在寫(xiě)之前瞎掰了一下，不用在意景鼠。

1.Node.js連接mongodb數(shù)據(jù)庫(kù)并創(chuàng)建集合

const MongoClient = require('mongodb').MongoClient;
let url = "mongodb://localhost:27017/datas";
MongoClient.connect(url,(err,db)=>{
  if(err){
    throw(err);
  }else{
    console.log('數(shù)據(jù)庫(kù)已連接');
    //db.close();
    let dbBase = db.db("datas");
    dbBase.createCollection("sec",(err,res)=>{
      if(err){
        throw(err);
      }else{
        console.log('創(chuàng)建集合');
      }
    });
  }
})

2.插入數(shù)據(jù)insert

const MongoClient = require('mongodb').MongoClient;
let url = 'mongodb://localhost:27017/datas';
let insertData =  function(db,callback){
  let collection = db.db('datas').collection('sec'); //連接到集合sec
  let data = [{title: 'mongodb',age: 15},{title: 'node.js',age: 18}];
  collection.insert(data,(err,res)=>{
    if(err){
      console.log(err);
      return;
    }else{
      callback(res);
    }
  });
}
MongoClient.connect(url,(err,db)=>{
  if(err){
    throw(err);
  }else{
    console.log('數(shù)據(jù)庫(kù)已連接');
    insertData(db,(res)=>{
      console.log(res);
    });
  }
})

3.查找數(shù)據(jù)find

const MongoClient = require('mongodb').MongoClient;
let url = 'mongodb://localhost:27017/datas';
let insertData =  function(db,callback){
  let collection = db.db('datas').collection('sec'); //連接到集合sec
  let data = {title: 'mongodb'};
  collection.find(data).toArray((err,res)=>{
    if(err){
      console.log(err);
      return;
    }else{
      callback(res);
    }
  });
}
MongoClient.connect(url,(err,db)=>{
  if(err){
    throw(err);
  }else{
    console.log('數(shù)據(jù)庫(kù)已連接');
    insertData(db,(res)=>{
      console.log(res[0].title);
    });
  }
})

4.刪除數(shù)據(jù)deleteMany,當(dāng)然,還有deleteOne

const MongoClient = require('mongodb').MongoClient;
let url = 'mongodb://localhost:27017/datas';
let insertData =  function(db,callback){
  let collection = db.db('datas').collection('sec'); //連接到集合sec //這里菜鳥(niǎo)教程直接寫(xiě)的db.collection是錯(cuò)的
  let data = {title: 'java教程'};
  collection.deleteMany(data,(err,res)=>{
    if(err){
      console.log(err);
      return;
    }else{
      callback(res);
    }
  });
}
MongoClient.connect(url,(err,db)=>{
  if(err){
    throw(err);
  }else{
    console.log('數(shù)據(jù)庫(kù)已連接');
    insertData(db,(res)=>{
      console.log(res);
    });
  }
})

5.更新數(shù)據(jù)update

const MongoClient = require('mongodb').MongoClient;
let url = 'mongodb://localhost:27017/datas';
let insertData =  function(db,callback){
  let collection = db.db('datas').collection('sec'); //連接到集合sec
  let data = {title: 'mongodb'}; //舊數(shù)據(jù)
  let updateData = {$set: {age: 20}}; //設(shè)置的新數(shù)據(jù)
  collection.update(data,updateData,(err,res)=>{
    if(err){
      console.log(err);
      return;
    }else{
      callback(res);
    }
  });
}
MongoClient.connect(url,(err,db)=>{
  if(err){
    throw(err);
  }else{
    console.log('數(shù)據(jù)庫(kù)已連接');
    insertData(db,(res)=>{
      console.log(res);
    });
  }
})