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Editor to share with you how to add nodejs and query database data, I believe that most people do not know much about it, so share this article for your reference, I hope you can learn a lot after reading this article, let's go to know it!

Add and query in database based on node.js

Train of thought

Create a project serverAPI

Initialize the project folder

Npm init-- y

Installation package

Npm i express mysql

Restfulf style

Testing with Postman software

[recommended: "nodejs tutorial"]

Project structure diagram

Realize

The sql.js file code is as follows:

/ / 1. Load msyqlvar mysql = require ('mysql'); / / 2. Create a connection var connection = mysql.createConnection ({host: 'localhost', / / the address of the database server you want to connect to: port: 3306 user / port number:' root', / / the user name required to connect to the database server password: 'root' / / password required to connect to the database server database: 'yanyan' / / the name of the database you want to connect to}) / / 3. Connect to the database connection.connect ((err) = > {/ / if there is an error object, the connection failed if (err) return console.log ('database connection failed') / / No error object indicates that the connection succeeded console.log ('mysql database connection succeeded')}; module.exports = connection

Server.js file reference code

Const express = require ("express"); const app = express (); const connection = require (". / utils/sql"); app.use (express.urlencoded ()); / / add data interface app.post ("/ api/student", (req, res) = > {console.log (req.body); / / receive common key pair parameter const {name, sex, age} = req.body / add to the database const sql = `insert into Students (name,sex,age) value ('${name}','${sex}', ${age}) `; / / console.log ("sql to be executed", sql); / / data accepted by result connection.query (sql, (err, result) = > {if (err) {console.log (err); res.json ({msg: "add failed", code: 0}) } else {console.log (result); res.json ({msg: "added successfully", code: 1});}}); / / get the data interface app.get ("/ api/student", (req, res) = > {const sql = `select * from Students `; connection.query (sql, (err, result) = > {if (err) {console.log (err)) Res.json ({msg: "acquisition failed", code: 0});} else {console.log (result); res.json ({msg: "get success", code: 0, data: result}); app.listen (3000, () = > {console.log ("API server starts, port number is 3000");})

Running result

Sql database

Postman test

Console output result

Optimization Scheme using routing Middleware

Train of thought

Create a project

Initialize the project folder

Npm init-- y

Installation package

Npm i express mysql

Restfulf style

Testing with Postman software

Project structure diagram

Realize

Sql.js file

/ / 1. Load mysqlvar mysql = require (". / node_modules/mysql"); / / 2. Create a connection var connection = mysql.createConnection ({host: "localhost", / / the address of the database server you want to connect to: port: 3306, / / the port number user: "root", / / the user name needed to connect to the database server password: "root", / / the password required to connect to the database server: "yanyan", / / the name of the database you want to connect to}); / / 3. Connect to the database connection.connect ((err) = > {/ / if there is an error object, if (err) return console.log ("database connection failure"); / / No error object indicates that the connection was successful console.log ("mysql database connection succeeded");}); module.exports = connection

Get.js file

Const connection = require (". / sql"); const express = require (". / node_modules/express"); const router = express.Router (); router.use (express.urlencoded ()); / / data acquisition API router.get ("/ api/student", (req, res) = > {const sql = `select * from Students`; connection.query (sql, (err, result) = > {if (err) {console.log (err)) Res.json ({msg: "acquisition failed", code: 0});} else {console.log (result); res.json ({msg: "get success", code: 0, data: result}); module.exports = router

Post.js file

Const connection = require (". / sql"); const express = require (". / node_modules/express"); const router = express.Router (); router.use (express.urlencoded ()); / / add data interface router.post ("/ api/student", (req, res) = > {/ / console.log (req.body); / / receive common key pair parameter const {name, sex, age} = req.body / add to the database const sql = `insert into Students (name,sex,age) values ('${name}','${sex}', ${age}) `; / / console.log ("sql to be executed", sql); / / data accepted by result connection.query (sql, (err, data) = > {if (err) {console.log (err); res.json ({msg: "add failed", code: 0}) } else {console.log (data); res.json ({msg: "added successfully", code: 1});}});}); module.exports = router

Server-pro.js file

Const get = require (". / utils/get"); const post = require (". / utils/post"); const express = require (". / node_modules/express"); const app = express (); app.use ("/ utils/get", get); app.use ("/ utils/post", post); app.listen (3000, () = > {console.log ("Interface server starts, port number is 3000");}) The above is all the contents of the article "how to add and query database data in nodejs". Thank you for reading! I believe we all have a certain understanding, hope to share the content to help you, if you want to learn more knowledge, welcome to follow the industry information channel!

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