MongoDB Node

墨蓝 2023-02-23 08:41 16阅读 0赞

[文档][Link 1]

前置工作：

1.  [安装][Link 2]本地mongoDB，并且启动「本地可以随便造」
2.  [安装][Link 3]可视化工具MongoDB Compass

## 开始啦 ##

新建一个本地空项目

npm init
    npm install mongoose --save

新建一个文件

// app.js
    // 第一步、链接mongo
    var mongoose = require('mongoose');
    mongoose.connect('mongodb://localhost/test');
    var db = mongoose.connection;
    db.on('error', console.error.bind(console, 'connection error:'));
    db.once('open', mongoOpen);
    // 第二部、成功回调里面进行操作
    async function mongoOpen() { 
      // we're connected!
      console.log('mongo open success');
      // 定义一个Schema，对应到mongo数据库的collection，类似于定义一个表
      // 当前Schema只有一个属性--name
      var kittySchema = mongoose.Schema({ 
        name: String
      });
      kittySchema.methods.speak = function () { 
        var greeting = this.name
          ? "Meow name is " + this.name
          : "I don't have a name";
        console.log(greeting);
      }
      var Kitten = mongoose.model('Kitten', kittySchema);
      // 新建数据
      var felyne = new Kitten({  name: 'Felyne' });
      // 就算添加其他属性，能够成功执行，但是不会保存上
      var fluffy = new Kitten({  name: 'fluffy' });
      var empty = new Kitten();
    
      // 添加
      await fluffy.save().then((v) => v.speak()); // 是个异步函数
      await empty.save();
      empty.speak();
      const saveRes = await felyne.save();
      felyne.speak();
      console.log('saveRes', saveRes);
      // => saveRes { _id: 5f02e434c4946e1642054c17, name: 'Felyne', __v: 0 }
    
      // 查询
      const list = await Kitten.find({  name: /^[fF]/})
      console.log('find res', list);
      console.log('find all res', await Kitten.find({ }));
    
      // 修改
      const updateRes = await Kitten.updateMany(
        {  name: undefined },
        {  name: 'fff' }
      );
      console.log('updateRes', updateRes);
      // => updateRes { n: 1, nModified: 1, ok: 1 }
      console.log('update find res', await Kitten.find({ }));
    
      // 删除
      const deleteRes = await Kitten.deleteMany({  name: /^[fF]/});
      console.log('deleteRes', deleteRes);
      // => deleteRes { n: 3, ok: 1, deletedCount: 3 }
      console.log('delete find res', await Kitten.find({ }));
    }

运行

node app.js

输出

mongo open success
    Meow name is fluffy
    I don't have a name Meow name is Felyne find res [ { _id: 5f02e30820b51d14acdfec20, name: 'fluffy', __v: 0 }, { _id: 5f02e30820b51d14acdfec1f, name: 'Felyne', __v: 0 } ] find all res [ { _id: 5f02e30820b51d14acdfec20, name: 'fluffy', __v: 0 }, { _id: 5f02e30820b51d14acdfec21, __v: 0 }, { _id: 5f02e30820b51d14acdfec1f, name: 'Felyne', __v: 0 } ] updateRes { n: 1, nModified: 1, ok: 1 } update find res [ { _id: 5f02e30820b51d14acdfec20, name: 'fluffy', __v: 0 }, { _id: 5f02e30820b51d14acdfec21, __v: 0, name: 'fff' }, { _id: 5f02e30820b51d14acdfec1f, name: 'Felyne', __v: 0 }
    ]
    deleteRes {  n: 3, ok: 1, deletedCount: 3 }
    delete find res []

[Link 1]: http://www.mongoosejs.net/docs/index.html
[Link 2]: https://www.runoob.com/mongodb/mongodb-osx-install.html
[Link 3]: https://www.mongodb.com/try/download/compass