1.新建一个数据库javamongotest 2.新建两个集合（user和owner），信息如下，要求：同时插入多个文档（insertMany） { "name" : “xiuxiu", "hobby" : "piano", “times”:6 } { "name" : chongyu", "hobby" : "basketball", “times”:5 } { "name" : "ruizhi", "hobby" : "books" “times”:3 }, { "name" :” yixin", "hobby" : " drawing" “times”:4 } { "name" : “yufeng", "hobby" : "music" “times”:6 } 2.向student集合插入如下文档 { "name" : “kefan", "hobby":”cloud computing”, times:1 } 3.统计文档user集合中的文档数量 4.查询name为kefan的文档，添加一个hobby属性 "likes":”helping others” 5.使用{name:"科凡"} 替换 name 为kefan 的文档 6.查询times>=5的user信息,并删除

1.新建一个数据库javamongotest，新建两个集合（user和owner）并插入多个文档

//连接数据库
var MongoClient = require('mongodb').MongoClient;
var url = "mongodb://localhost:27017/javamongotest";

MongoClient.connect(url, function(err, db) {
  if (err) throw err;
  console.log("数据库已创建!");
  var dbo = db.db("javamongotest");

  //插入多个文档到user集合
  var userArr = [
    { "name" : "xiuxiu", "hobby" : "piano", "times":6 },
    { "name" : "chongyu", "hobby" : "basketball", "times":5 },
    { "name" : "ruizhi", "hobby" : "books", "times":3 },
    { "name" : "yixin", "hobby" : "drawing", "times":4 },
    { "name" : "yufeng", "hobby" : "music", "times":6 }
  ];
  dbo.collection("user").insertMany(userArr, function(err, res) {
    if (err) throw err;
    console.log("插入的文档数量为: " + res.insertedCount);
    db.close();
  });

  //插入一个文档到owner集合
  var ownerObj = { "name" : "Tom", "age" : 20, "address" : "北京市朝阳区" };
  dbo.collection("owner").insertOne(ownerObj, function(err, res) {
    if (err) throw err;
    console.log("文档插入成功");
    db.close();
  });
});

2.向user集合插入一个文档

//连接数据库
var MongoClient = require('mongodb').MongoClient;
var url = "mongodb://localhost:27017/javamongotest";

MongoClient.connect(url, function(err, db) {
  if (err) throw err;
  console.log("数据库已创建!");
  var dbo = db.db("javamongotest");

  //插入一个文档到user集合
  var userObj = { "name" : "kefan", "hobby": "cloud computing", "times": 1 };
  dbo.collection("user").insertOne(userObj, function(err, res) {
    if (err) throw err;
    console.log("文档插入成功");
    db.close();
  });
});

3.统计文档user集合中的文档数量

//连接数据库
var MongoClient = require('mongodb').MongoClient;
var url = "mongodb://localhost:27017/javamongotest";

MongoClient.connect(url, function(err, db) {
  if (err) throw err;
  console.log("数据库已创建!");
  var dbo = db.db("javamongotest");

  //统计user集合中的文档数量
  dbo.collection("user").countDocuments(function(err, count) {
    if (err) throw err;
    console.log("user集合中的文档数量为: " + count);
    db.close();
  });
});

4.查询name为kefan的文档，添加一个hobby属性"likes":"helping others"

//连接数据库
var MongoClient = require('mongodb').MongoClient;
var url = "mongodb://localhost:27017/javamongotest";

MongoClient.connect(url, function(err, db) {
  if (err) throw err;
  console.log("数据库已创建!");
  var dbo = db.db("javamongotest");

  //查询name为kefan的文档，并添加一个hobby属性"likes":"helping others"
  dbo.collection("user").findOneAndUpdate(
    { "name": "kefan" },
    { $set: { "likes": "helping others" } },
    function(err, res) {
      if (err) throw err;
      console.log("文档更新成功");
      db.close();
    }
  );
});

5.使用{name:"科凡"} 替换 name 为kefan 的文档

//连接数据库
var MongoClient = require('mongodb').MongoClient;
var url = "mongodb://localhost:27017/javamongotest";

MongoClient.connect(url, function(err, db) {
  if (err) throw err;
  console.log("数据库已创建!");
  var dbo = db.db("javamongotest");

  //使用{name:"科凡"}替换name为kefan的文档
  dbo.collection("user").updateOne(
    { "name": "kefan" },
    { $set: { "name": "科凡" } },
    function(err, res) {
      if (err) throw err;
      console.log("文档替换成功");
      db.close();
    }
  );
});

6.查询times>=5的user信息，并删除

//连接数据库
var MongoClient = require('mongodb').MongoClient;
var url = "mongodb://localhost:27017/javamongotest";

MongoClient.connect(url, function(err, db) {
  if (err) throw err;
  console.log("数据库已创建!");
  var dbo = db.db("javamongotest");

  //查询times>=5的user信息，并删除
  var query = { "times": { $gte: 5 } };
  dbo.collection("user").deleteMany(query, function(err, obj) {
    if (err) throw err;
    console.log(obj.result.n + " 条文档被删除");
    db.close();
  });
});