Mysql 我在heroku上部署api后出现此错误；连接EConrefuse127.0.0.1:3306“；

虽然我将配置变量存储在heroku设置中，但我认为它无法连接到我的数据库

错误

const Sequelize = require('sequelize');

const sequelize = new Sequelize(`${process.env.SQL_DB}`, 'root', `${process.env.SQL_Password}`, {
    dialect: 'mysql',
    host: 'localhost'
});

module.exports = sequelize;

---

mysql

DB是否正在运行？？是的，其运行代码在本地主机上运行良好，但在服务器端出现get错误您的数据库将不会在

localhost

上运行。您使用的是什么MySQL插件？MySQL是否正在运行？是的，它的运行代码在本地主机上运行得很好，但在服务器端出现get错误您的数据库不会在本地主机上运行。你在使用什么MySQL插件？

Unhandled rejection SequelizeConnectionRefusedError: connect ECONNREFUSED 127.0.0.1:3306
2020-01-07T10:27:38.586244+00:00 app[web.1]:     at /app/node_modules/sequelize/lib/dialects/mysql/connection-manager.js:139:19
2020-01-07T10:27:38.586246+00:00 app[web.1]:     at tryCatcher (/app/node_modules/bluebird/js/release/util.js:16:23)
2020-01-07T10:27:38.586248+00:00 app[web.1]:     at Promise._settlePromiseFromHandler (/app/node_modules/bluebird/js/release/promise.js:547:31)
2020-01-07T10:27:38.586250+00:00 app[web.1]:     at Promise._settlePromise (/app/node_modules/bluebird/js/release/promise.js:604:18)
2020-01-07T10:27:38.586252+00:00 app[web.1]:     at Promise._settlePromise0 (/app/node_modules/bluebird/js/release/promise.js:649:10)
2020-01-07T10:27:38.586254+00:00 app[web.1]:     at Promise._settlePromises (/app/node_modules/bluebird/js/release/promise.js:725:18)
2020-01-07T10:27:38.586256+00:00 app[web.1]:     at _drainQueueStep (/app/node_modules/bluebird/js/release/async.js:93:12)
2020-01-07T10:27:38.586258+00:00 app[web.1]:     at _drainQueue (/app/node_modules/bluebird/js/release/async.js:86:9)
2020-01-07T10:27:38.586260+00:00 app[web.1]:     at Async._drainQueues (/app/node_modules/bluebird/js/release/async.js:102:5)
2020-01-07T10:27:38.586262+00:00 app[web.1]:     at Immediate.Async.drainQueues [as _onImmediate] (/app/node_modules/bluebird/js/release/async.js:15:14)
2020-01-07T10:27:38.586264+00:00 app[web.1]:     at processImmediate (internal/timers.js:439:21)