安装

npm install mongodb --save

连接数据库

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

// Connection URL
const url = 'mongodb://localhost:27017';

// Database Name
const dbName = 'myproject';

// Use connect method to connect to the server
MongoClient.connect(url, function(err, client) {
  assert.equal(null, err);
  console.log("Connected successfully to server");

  const db = client.db(dbName);

  client.close();
});

插入文档

const insertDocuments = function(db, callback) {
  // Get the documents collection
  const collection = db.collection('documents');
  // Insert some documents
  collection.insertMany([
    {a : 1}, {a : 2}, {a : 3}
  ], function(err, result) {
    assert.equal(err, null);
    assert.equal(3, result.result.n);
    assert.equal(3, result.ops.length);
    console.log("Inserted 3 documents into the collection");
    callback(result);
  });
}

查找所有文档

const findDocuments = function(db, callback) {
  // Get the documents collection
  const collection = db.collection('documents');
  // Find some documents
  collection.find({}).toArray(function(err, docs) {
    assert.equal(err, null);
    console.log("Found the following records");
    console.log(docs)
    callback(docs);
  });
}

更新文档

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

// Connection URL
const url = 'mongodb://localhost:27017';

// Database Name
const dbName = 'myproject';

// Use connect method to connect to the server
MongoClient.connect(url, function(err, client) {
  assert.equal(null, err);
  console.log("Connected successfully to server");

  const db = client.db(dbName);

  insertDocuments(db, function() {
    updateDocument(db, function() {
      client.close();
    });
  });
});

删除文档

const removeDocument = function(db, callback) {
  // Get the documents collection
  const collection = db.collection('documents');
  // Delete document where a is 3
  collection.deleteOne({ a : 3 }, function(err, result) {
    assert.equal(err, null);
    assert.equal(1, result.result.n);
    console.log("Removed the document with the field a equal to 3");
    callback(result);
  });
}

mongoose使用

链接数据库

mongoose.connect('mongodb://localhost:27017/itcast', {useNewUrlParser: true, useUnifiedTopology: true});

设计表结构

const Schema = mongoose.Schema
const userSchema = new Schema({
  username:{
    type:String,
    required:true
  },
  password:{
    type:String,
    required:true
  },
  email:{
    type:String
  }
});

将文档结构发布为模型

第一个参数要大写,最终数据库中会将该字符串变为该字符串的小写的复数(users)

const User = mongoose.model('User', userSchema)

对模型进行增删改查

新增数据

var admin = new User({
  username:'admin',
  password:'123',
  email:'1225348331@qq.com'
})
//对数据进行持久化
admin.save(function(err,result){
  if(err){
    console.log('存储失败')
  }
  console.log('保存成功了')
  console.log(result)
})

查询数据

//第一个参数为查询条件
User.find({
  username:"admin",
  password:"123"
},function(err,data){
  if(err){
    console.log(err)
  }
  console.log(data)
})