前言
由于工作需要，设计到了阿里云的弹性计算，这里便记录下来
技术栈
- node.js
- postgresql
- nodemailer
controller + services
编写postgresql lib
不管异常还是正常都返回resolve，在resolve中处理结果，通过success字段去处理
const { Pool } = require('pg');
const config = require('../config/default.js');
const {
database: {
HOST,
PORT,
DATABASE,
USERNAME,
PASSWORD,
},
} = config;
const pool = new Pool({
port: PORT,
host: HOST,
user: USERNAME,
password: PASSWORD,
database: DATABASE,
});
/**
*
* @param sql 接收的sql语句
* @param {Array} values sql语句参数
* @return { Object } { success: boolean, err || data }
*/
const query = async function( sql = 'select NOW()', values = []) {
return new Promise(resolve => {
pool.connect((err, client, release) => {
if (err) {
return console.error('Error acquiring client', err.stack)
}
const params = Array.isArray(values) ? [...values] : [values];
client.query(sql, params, (error, result) => {
release();
if (error) {
console.error('Error executing query', error.stack);
resolve({
success: false,
error,
});
}
resolve({
success: true,
data: result.rows,
});
});
});
});
}
module.exports = {
query,
}
config配置文件如下
const config = {
// 数据库配置
database: {
DATABASE: 'databasename',
USERNAME: 'root',
PASSWORD: '123456',
PORT: '3433',
HOST: 'localhost',
},
};
module.exports = config;
Controller
BaseController
首先编写一个基类，用于封装一些通用的方法
const pool = require('../lib/postgre'); // 导入封装好的mysql库
const { query } = pool; // 导入query方法
class BaseController {
constructor() {
}
// 查询表内所有数据（非删除）
async list() {
const sql = `select * from ${this.table}`;
return await query(sql);
}
async excute(sql, vals = []) {
// 执行方法
return await query(sql, vals);
}
// log 方法
log({func, err}) {
console.log(`excute function[${func}] occured error : ${err.message || err}`);
}
}
module.exports = BaseController;
InqueryController
具体的业务逻辑Controller类
const BaseController = require('./BaseController'); // 获得基类
// 继承基类
class InqueryController extends BaseController {
constructor() {
super();
this.table = 'data_table'; // 赋值table
}
// 可以重写基类的方法，如果有业务需要
async list() {
const sql = `select * from ${this.table} ORDER BY created_at DESC `;
return await this.excute(sql);
}
async getUnsendCustomer(vals) {
const sql = `select * from ${this.table} where created_at > $1 ORDER BY created_at DESC`;
// 统一在基类调用sql参数
return await this.excute(sql, vals);
}
}
module.exports = InqueryController;
Service
BaseService
统一封装的方法，基类
// 需要绑定this的方法
const funcs = [
'list',
]
class BaseService {
constructor() {
this.controller = null;
// 循环遍历绑定this, 在koa绑定route的时可用到
funcs.forEach(item => {
this[item] = this[item].bind(this)
});
}
// 查询方法
async list(ctx) {
if (!ctx) {
return await this.controller.list();
}
// controller返回的是一个对象，success(成功为true， 失败为false), data(成功则有此数据), err(失败则有此对象)
const { success: flag, data, error } = await this.controller.list();
if (flag) {
// success
ctx.body = {
data,
code: 200,
}
} else {
// failed
ctx.body = {
code: 500,
error,
};
}
}
}
module.exports = BaseService
InqueryService
具体的业务逻辑
// 导入基类
const BaseService = require('./BaseService');
// 导入对应的controller
const Controller = require('../controller/InqueryController');
// 获取MailSender Service
const MailService = require('./MailSender');
const Helper = require('../util/Helper');
const funcs = [
'unsendUser',
];
// 生成一次controller
const controller = new Controller();
class InqueryService extends BaseService {
constructor() {
super()
// 绑定对应的controller
this.controller = controller;
funcs.forEach(item => {
this[item] = this[item].bind(this);
});
}
getMailOpts(i) {
// you can use the data from database to combine the message
const message = 'Hello world!';
return return {
message,
// 可以从配置文件读取或者oss
to: 'xxxx@gmail.com',
subject: 'Hello World',
};
}
async unsendUser() {
const list = await this.controller.list();
if (list.length > 0) {
const mailer = new MailService();
const errorList = [];
iterateList.forEach(async i => {
const mailerOption = this.getMailOpts(i);
const { success, ...rest } = await mailer.sendToAuitAdmin(mailerOption);
if (!success) {
errorList.push(rest);
}
});
const lastestTime = iterateList[0].created_at;
if (errorList.length === 0) {
return {
code: 200,
message: 'Success',
};
}
} else {
return {
code: 204,
message: 'No user found',
};
}
}
}
module.exports = new InqueryService();
index.js
函数计算的逻辑
const inqueryService = require('./services/InqueryService');
exports.handler = async function(event, context, callback) {
const result = await inqueryService.unsendUser();
callback(null, result);
};
总结
以上就是这篇文章的全部内容了，希望本文的内容对大家的学习或者工作具有一定的参考学习价值，如果有疑问大家可以留言交流，谢谢大家对找一找教程网的支持。
