mysql.js

const Sequelize = require('sequelize')
const fs = require('fs')
const path = require('path')

let database = null

const loadModels = (sequelize) => {
    const dir = path.join(__dirname, '../modules/models')
    const models = []

    fs.readdirSync(dir).forEach((file) => {
        const modelDir = path.join(dir, file)
        const model = sequelize.import(modelDir)
        models[model.name] = model
    })

    Object.keys(models).forEach(function (object) {
        if ('associate' in models[object]) {
            models[object].associate(models)
        };
    })

    return models
}

module.exports = (app) => {
    if (!database) {
        const config = app.config
        const sequelize = new Sequelize(
            config.database,
            config.username,
            config.password,
            config.params
        )
        database = {
            sequelize,
            Sequelize,
            models: {}
        }

        database.models = loadModels(sequelize)
        sequelize.sync().done(() => database)
    }
    return database
}