1.创建egg项目并启动后端服务器

pnpm create egg    //创建项目
//选择simple就行
pnpm i    //下载插件
pnpm run dev    //运行项目

2.安装跨域依赖和数据库依赖

pnpm i egg-cors    //跨域依赖
pnpm i egg-mysql    //数据库依赖
pnpm i egg-scripts  //部署

3.修改配置文件 plugin.js

module.exports = {// had enabled by egg// static: {//   enable: true,// }mysql:{enable:true,package:'egg-mysql'},cors:{enable:true,package:'egg-cors'}
};

4.配置config.default.js

module.exports = appInfo => {/*** built-in config* @type {Egg.EggAppConfig}**/const config = exports = {};// use for cookie sign key, should change to your own and keep securityconfig.keys = appInfo.name + '_1709895338474_7197';// add your middleware config hereconfig.middleware = [];// add your user config hereconst userConfig = {// myAppName: 'egg',};//关闭CSRF验证  跨域请求  不进行同源验证config.security = {csrf:{enable:false}}config.cors = {origin: '*',allowMethods: 'GET,POST,PUT,DELETE' //设置允许访问的请求方式}//配置数据库连接config.mysql = {app:true,client:{host:'localhost', //数据库地址port:'3306', //数据库端口号user:'root',   //数据库用户名password:'123456', //数据库密码database:'mitest',  //要连接的数据库}}return {...config,...userConfig,};
};

5.配置service层

const  Service  = require("egg").Service;class CustomerService extends Service {//4.登录（根据客户手机号码和密码进行查询）async selectCustomerByTelIdByPass(customer) {let result;try {//调用数据库实现查询let sql = `select * from customer where telId=${customer.telId} and password=${customer.password}`;  result = await this.app.mysql.query(sql);} catch (error) {console.log(error)}return result;}
}module.exports = CustomerService;

6.配置controller层

const { Controller } = require("egg");class CustomerController extends Controller {//1.全查询所有的商品分类信息async selectCustomerByTelIdByPass() {const { ctx } = this; //对应的application实例  全局//调用service层方法得到结果  返回给前台const result = await this.ctx.service.customer.selectCustomerByTelIdByPass(this.ctx.request.body);ctx.body = result}
}module.exports = CustomerController

7.配置路由层

 router.post('/selectUserByUserByPass' , controller.userinfo.selectUserByUserByPass)