使用 Mysql

既然已经能搭起服务了，那就要考虑数据存储了。关系型数据库的话以 Mysql 为例

本文不讲如何去配置 Mysql，而是讲如何通过 Koa 来连接并使用数据库，这里使用 npm 的 ORM 模块sequelize来简单地做个示例，献上文档

cnpm install mysql2 -D
cnpm install sequelize -D

dbConfig.js

module.exports = {
  host:'localhost',
  port:3306,
  user:'test',
  password:'123456',
  database:'comang',
}

model.js

const Sequelize = require('sequelize');
const dbConfig = require('./dbConfig');

// 连接数据库
var sequelize = new Sequelize(dbConfig.database, dbConfig.user, dbConfig.password, {
  host: dbConfig.host,
  dialect: 'mysql',
  pool: {
    max: 5,
    min: 0,
    idle: 30000
  },
  operatorsAliases: false,
});

// 定义模型
var model = sequelize.define('order', {
  id: {
    type: Sequelize.INTEGER,
    primaryKey: true,
    autoIncrement: true,
  },
  goodsname: Sequelize.STRING,
  price: Sequelize.DOUBLE,
  amount: Sequelize.INTEGER,
  ordertime: Sequelize.DATE,
}, {
  timestamps: false
});

module.exports = model;

app.js

const model = require('./model');

app.use(async (ctx, next) => {
    let list = await model.findAll();
    for(let e of list){
      console.log(e.goodsname);
    }
    ctx.body = JSON.stringify(list);
});