Sequelize 'Dialect needs to be explicitly supplied as of v4.0.0' - node.js

Question

I need to run third party application in node.js environment but Sequelize throws 'Dialect needs to be explicitly supplied as of v4.0.0'
I've found similar topic here Dialect needs to be explicitly supplied as of v4.0.0 but 'export NODE_ENV=development' doesn't work and I can not find Sequelize config file.
How can I fix this error?
Here is code:
const Sequelize = require('sequelize');
const scheme = require('./scheme');
const Op = Sequelize.Op;
const sequelize = new Sequelize(null, null, {
dialect: 'sqlite',
storage: 'db.sqlite3',
operatorsAliases: { $and: Op.and },
logging: false
});
scheme(sequelize);
sequelize.sync();
module.exports.sequelize = sequelize;
module.exports.models = sequelize.models;

Answer 1

You simply supply the dialect when you initialize sequelize;
const sequelize = new Sequelize('database', 'username', 'password', {
host: 'localhost',
dialect: // pick one of 'mysql','sqlite','postgres','mssql',
});

Answer 2

Node cannot find your environment to load in the config file.
You can easily fix by running this
export NODE_ENV=development; npx sequelize db:migrate
This should export to NODE_ENV the environment needed to run it.

Answer 3

this worked for me:
'use strict';
const path = require('path');
const Sequelize = require('sequelize');
const db = {};
const DB = 'users';
const USER = 'user';
const PASSWORD = 'password';
const HOST = 'host';
const DIALECT = 'postgres';
const PORT = 5432;
const CONNECTION = new Sequelize(
DB,
USER,
PASSWORD,
{
host: HOST,
dialect: DIALECT,
port: PORT,
}
)
module.exports.CONNECTION = CONNECTION;

Answer 4

I think you already have solved the problem. But I faced the same issue.
My issue had happened due to the name change of the config file that is auto generated by the sequelize-cli. So what I eventually did was, I created a .sequelizerc file in the project root folder and include following content.
const path = require('path');
module.exports = {
'config': path.resolve('config', 'database.json'),
'models-path': path.resolve('db', 'models'),
'seeders-path': path.resolve('db', 'seeders'),
'migrations-path': path.resolve('db', 'migrations')
};
Make sure to change the arguments according to your folder structure of the project.
A comprehensive explanation has on the sequelize documentation page.
https://sequelize.org/master/manual/migrations.html