var MongoClient = require('mongodb').MongoClient;
var assert = require('assert');

//连接test数据库
var url = 'mongodb://localhost:27017/test';
MongoClient.connect(url, (err,db) => {
 assert.equal(null,err);
 console.log('连接成功');
 db.close();
});

var MongoClient = require('mongodb').MongoClient;
var assert = require('assert');

//test数据库的路径
var url = 'mongodb://localhost:27017/test';

//插入文档
var insertDocument = (db,callback) => {
 //在test库下blog集合中 新增json文档
 db.collection('blog').insertOne({
  name:"xiaos",
  age:22
 }, (err, result) => {
  assert.equal(err,null);
  console.log('新增文档成功');
  callback();
 });
};

 
//插入操作
MongoClient.connect(url, (err,db) => {
 assert.equal(null,err);
 insertDocument(db, ()=>{
  db.close();
 });
});

var MongoClient = require('mongodb').MongoClient,
 test = require('assert');

MongoClient.connect('mongodb://localhost:27017/test',(err, db) => {
 var blog = db.collection('blog');
 //新增两个文档对象
 blog.insertMany([{name:"shen"},{name:"fzq"}],(err,r) => {
  test.equal(null,err);
  //回调函数中返回的r为执行完插入操作的对象，insertedCount属性为已经插入的对象个数
  test.equal(2,r.insertedCount);
  db.close();
 });
}); 

var MongoClient = require('mongodb').MongoClient,
 test = require('assert');
MongoClient.connect('mongodb://localhost:27017/test', (err,db) => {
 var blog = db.collection('blog');
 blog.insertMany([{name:"xiaosGG"},{name:"fzqDD"}]).then((r) => {
  test.equal(2,r.insertedCount);
  db.close();
 });
});

var MongoClient = require('mongodb').MongoClient,
 test = require('assert'),
 co = require('co');
 
co(function*(){
 var db = yield MongoClient.connect('mongodb://localhost:27017/test');
 var blog = db.collection('blog');
 var r = yield blog.insertMany([{name:"xiaosBB"},{name:"fzqMM"}]);
 test.equal(2,r.insertedCount);
 db.close();
});

var MongoClient = require('mongodb').MongoClient,
 test = require('assert');
MongoClient.connect('mongodb://localhost:27017/test',(err,db)=>{
 var blog = db.collection('blog');
 blog.insertOne({name:"xiaos"},(err,r) => {
  test.equal(null,err);
  test.equal(1,r.insertedCount);
  db.close();
 });
});

var MongoClient = require('mongodb').MongoClient,
 test = require('assert');
MongoClient.connect('mongodb://localhost:27017/test',(err,db)=>{
 var blog = db.collection('blog');
 blog.insertOne({name:"xiaos"}).then((r)=>{
  test.equal(1,r.insertedCount);
  db.close();
 });
});

var MongoClient = require('mongodb').MongoClient,
 test = require('assert'),
 co = require('co');
 
co(function*(){
 var db = yield MongoClient.connect('mongodb://localhost:27017/test');
 var blog = db.collection('blog');
 var r = yield blog.insertOne({name:"xiaosBB"});
 test.equal(1,r.insertedCount);
 db.close();
});

var MongoClient = require('mongodb').MongoClient,
 test = require('assert');

MongoClient.connect()

var MongoClient = require('mongodb').MongoClient,
 test = require('assert');
MongoClient.connect('mongodb://localhost:27017/test',(err,db) => {
 db.createCollection('newBlog',{'capped':true,'size':1024},(err,collection) => {
  test.equal('newBlog',collection.collectionName);  
  collection.isCapped((err,capped) => {
   test.equal(true,capped);
   db.close();
  });
 });
});

//在命令行中输入mongo
//创建一个1024大小的myCappedCollection集合
db.createCollection('myCappedCollection',{'capped':true,'size':1024});
//插入1000条记录
for (var i = 1;i <= 1000;i++){
 db.myCappedCollection.save({id:i,name:'xiaos'+i});
}
//查询文档个数
db.myCappedCollection.count()
//实际只有18个文档id为983-1000 即新元素覆盖了旧元素