JS Objects to MySQL

js_object_version.js

const subscribers = {};

module.exports = subscriptions = {

    subscribe: function(clientId, dataId) {

        // Add subscribed user/data to the subscriptions object
        const user = subscribers[clientId] || {};
        user[dataId] = true;
        subscribers[clientId] = user;

    },

    unsubscribe: function(clientId, dataId) {

        // If the client isn't subscribed to anything just return
        if (!subscribers[clientId]) return [];

        // If no data id is specified the entire subscriber is destroyed
        if (!dataId) {

            var unsubscribedDataIds = Object.keys(subscribers[clientId]);

            delete subscribers[clientId];

            return unsubscribedDataIds;

        }

        // Remove individual data point from general subscribers list
        if (subscribers[clientId]) {
            delete subscribers[clientId][dataId];
            return [dataId];
        }

        // No subscriptions found
        return [];

    },

    getSubscriptions: function(clientId){

        if (subscribers[clientId]) {
            return subscribers[clientId];
        }

        return false;

    },

}

mysql_version.js

const { query, esc } = require('./helpers/config.js');

// Add subscriber to db
export function subscribe(clientId, dataId) {
    return query(`
        INSERT INTO store_subscribers
        SET client_id = ${esc(clientId)},
        data_id = ${esc(dataId)}
        ON DUPLICATE KEY
        UPDATE data_id = ${esc(dataId)}
        `);
}

// Remove subscriber to db
export async function unsubscribe(clientId, dataId) {
    var sql = `
        DELETE FROM store_subscribers
        WHERE client_id = ${esc(clientId)}
        `;

    if (dataId) sql = sql.concat(` AND data_id = ${esc(dataId)}`);

    return query(sql);
}

// Return the subscriptions for a specific clientId
export function getSubscriptions(clientId) {
    return query(`
        SELECT * FROM store_subscribers
        WHERE client_id = ${esc(clientId)}
        `);
}

// Get all the subscribers for a data point
export function getDataSubscriptions(dataId) {
    return query(`
        SELECT * FROM store_subscribers
        WHERE data_id = ${esc(dataId)}
        `);
}