1. First install node globally; execute npm -v;
npm -v
2. Initialize the project: npm init, you will see a package.json file;
npm init
3. Execute npm install;
npm install
4. Download express, body-parser, mysql;
npm install express body-parser mysql--save
or
cnpm install express --save
5. Create a new index.js or other js file with any name in parallel with the package.json directory;
then write in this file:
const express = require('express');
const app = express();
const mysql = require('mysql');
const bodyParser = require('body-parser');
const urlLib = require('http');
app.use(bodyParser.json());
app.use(bodyParser.urlencoded({ extended: true }))
//mysqlOption 这里应该写到配置文件中，后续再讲这块
const mysqlOption = {
host: 'xxx',
user: 'root',
password: '123456',
database: 'test'
}
let con = mysql.createConnection(mysqlOption)
app.get('/query', (req, res) => {
const sql = `select * from xxx`; //数据库的sql语句
var parseObj = urlLib.parse(req.url, true); //get请求参数
//拿到get请求(例如参数为id，则获取参数id=parseObj.query.id)，对请求的参数做判断或者逻辑处理
try {
con.query(sql, (require, response) => {
//返回给前端的数据
res.json(new Result({ data: response }))
})
} catch {
res.json(new Result({ code: '0', msg: '请求失败' }))
}
})
app.post('/query', (req, res) => {
const sql = `select * from xxx`; //数据库的sql语句
const params = req.body; //post 请求的参数
//拿到post请求params(例如参数为name,获取参数name=params.name)，对请求的参数做判断或者逻辑处理
try {
con.query(sql, (require, response) => {
//返回给前端的数据
res.json(new Result({ data: response }))
})
} catch {
res.json(new Result({ code: '0', msg: '请求失败' }))
}
})
function Result({ code = '1', msg = '请求成功', data = {} }) {
this.code = code;
this.msg = msg;
this.data = data;
}
const port = process.env.port || '3000';
app.set('port', port)
app.listen(80, () => {
console.log("服务启动了")
})
//请求url找不到，设置请求状态为404
app.use((req, res) => {
res.sendStatus(404)
})
7. Start the service npm start;
npm start
8. Use postman to call directly: For example, the local ip is 10.10.10.10:
then splicing 10.10.10.10/query, you can call the above get request.
Next article "Router Application of Node.js Backend Service"