nodejs addition, deletion and modification

Node.js is a JavaScript running environment built on the Chrome V8 engine, which allows JavaScript code to run on the server side. It is very common to perform addition, deletion and modification operations in Node.js. This article will introduce how to use Node.js to perform addition, deletion and modification operations.

1. Add data

To add data in Node.js, you need to use a database module. Commonly used ones include Mongoose, Sequelize, etc. This article uses Mongoose as an example to introduce.

1. Install Mongoose

Run the following command in the command line to install:

npm install mongoose --save

2. Connect to the database

First you need to connect to the MongoDB database, the code is as follows:

const mongoose = require('mongoose'); mongoose.connect('mongodb://localhost/test', { useNewUrlParser: true, useUnifiedTopology: true });

Among them,mongodb://localhost/testmeans connecting to the local MongoDB database named test.

3. Create data model

To use Mongoose, you need to define the data model first. You can create auser.js# in themodelsfolder. ## file, the code is as follows:

const mongoose = require('mongoose'); const userSchema = new mongoose.Schema({ name: String, age: Number }); module.exports = mongoose.model('User', userSchema);

userSchemadefines the user's name and age attributes.

Add data

const User = require('./models/user'); const user = new User({ name: 'John', age: 25 }); user.save((err) => { if (err) { console.log(err); } else { console.log('User created'); } });

user.save()Save the newly added user data to the MongoDB database.

Delete data

const User = require('./models/user'); User.deleteOne({ name: 'John' }, (err) => { if (err) { console.log(err); } else { console.log('User deleted'); } });

User.deleteOne()means to delete the data whosenameisJohnin the user attribute.

Modify data

const User = require('./models/user'); User.findOneAndUpdate({ name: 'John' }, { age: 26 }, (err, user) => { if (err) { console.log(err); } else { console.log('User updated'); } });

User.findOneAndUpdate()means to find the data whosenameisJohnin the user attribute, and modify theageattribute to26.

The above is the detailed content of nodejs addition, deletion and modification. For more information, please follow other related articles on the PHP Chinese website!