npm  install  express --save 
//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" ) ; 
} ) ; 
npm  i mysql
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` ( "Successfully connected to the database." ) ; 
} ) ; 
app.listen( 8081 , ( )  = >  { 
  console.log( "http://localhost:8081" ) ; 
} ) ; 
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` ( "/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 = "${config_name} " ` ( 
    ` SELECT * FROM config  where config_name = "${config_name} " ` ( error, results, fields)  = >  { 
      if  ( error)  throw error; 
      // 发送响应
      res.send( results) ; 
    } 
  ) ; 
} ) ; 
app.listen( 8081 , ( )  = >  { 
  console.log( "http://localhost:8081" ) ; 
} ) ;