express连接mysql

一、 安装express

npm install express --save

二、express配置

//引入
const express = require("express");
//创建实例
const app = express();
//启动服务
app.listen(8081, () => {
  console.log("http://localhost:8081");
});

三、安装mysql

npm i mysql

四、配置到express中

const express = require("express");
const mysql = require("mysql"); //引入mysql
const app = express();
// 设置MySQL连接配置
const connection = mysql.createConnection({
  host: "localhost", 
  user: "root",  //数据库账号
  password: "root", //数据库密码
  database: "deli", //数据库名称
});
// 连接到MySQL数据库
connection.connect((error) => {
  if (error) throw error;
  //连接成功打印结果`如果连接失败，记得查看数据库是否开启`
  console.log("Successfully connected to the database.");
});
app.listen(8081, () => {
  console.log("http://localhost:8081");
});

五、加入get请求

const express = require("express");
const mysql = require("mysql");
const app = express();
// 设置MySQL连接配置
const connection = mysql.createConnection({
  host: "localhost",
  user: "root",
  password: "root",
  database: "deli",
});
// 连接到MySQL数据库
connection.connect((error) => {
  if (error) throw error;
  console.log("Successfully connected to the database.");
});


`这里为增加的get请求内容`
app.get("/testApi", (req, res) => {
  //获取到请求参数
  const { config_name } = req.query;
  //去表名称为config的表中去查数据 ，查询条件为`config_name="${config_name}"`，其中双引号不可省去
  connection.query(
    `SELECT * FROM config  where config_name="${config_name}"`,
    (error, results, fields) => {
      if (error) throw error;
      // 发送响应
      res.send(results);
    }
  );
});

app.listen(8081, () => {
  console.log("http://localhost:8081");
});

六、前端请求接口