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How to store data from a MariaDB in my node.js environment

I have a MariaDB that stores Energy-Data like voltage, frequency and so on. My aim is to visualize the data in a Web-application. Though i achieved to connect the MariaDB to node.js and log the data on a specific port thanks to the code below, i don't have a clue how to store this data for further mathematic operations or visualizations.
How can i store the data for further operations?
const express = require('express');
const pool = require('./db');
const app = express();
const port = 4999;
// expose an endpoint "persons"
app.get('/persons', async (req, res) => {
let conn;
try {
// make a connection to MariaDB
conn = await pool.getConnection();
// create a new query to fetch all records from the table
var query = "select * from Herget_Netz2_WirkleistungL1";
// run the query and set the result to a new variable
var rows = await conn.query(query);
console.log('Daten kommen');
// return the results
res.send(rows);
} catch (err) {
throw err;
} finally {
if (conn) return conn.release();
}
});
app.listen(port, () => console.log(`Listening on pfort ${port}`));

This question is quite broad.
It sounds like you need to set up a frontend and call fetch on your endpoint, something like:
fetch(<your-url>/persons)
.then(r => r.json())
.then(yourData => "<p>" + yourData "</p>")
Your data will be interpolated into HTML then. You will need to iterate over it.
The "storage" will take place in the variable you define in the second .then(yourData) of the promise for you to do further operations on.
You should search for tutorials like "set up frontend with maria db database and node backend".

Node.Js MSSQL Query Timeout Expired

I am using Node Express API to run SQL queries to populate a dashboard of data. I am using the mssql-node package to do so. Sometimes it runs flawlessly, other times I get the following error:
[Error: [Microsoft][SQL Server Native Client 11.0]Query timeout expired]
I am creating a poolPromise with a connectionPool to the db, then I pass that object to my other controllers which run the specific queries to populate data. I run the server which initiates the db.js script and connects to MSSQL with a pool connection.
db.js:
// for connecting to sql server
const sql = require('mssql/msnodesqlv8');
// db config to connect via windows auth
const dbConfig = {
driver: 'msnodesqlv8',
connectionString: 'Driver={SQL Server Native Client 11.0};Server={my_server};Database={my_db};Trusted_Connection={yes};',
pool: {
idleTimeoutMillis: 60000
}
};
// create a connectionpool object to pass to controllers
// this should keep a sql connection open indefinitely that we can query when the server is running
const poolPromise = new sql.ConnectionPool(dbConfig)
.connect()
.then(pool => {
console.log('Connected to MSSQL');
return pool;
})
.catch(err => console.log('Database Connection Failed! Bad Config: ', err))
module.exports = { sql, poolPromise };
An example of one of my controllers and how I use the poolPromise object is below. I currently have about 7 of these controllers that run their own specific query to populate a specific element on the dashboard. The performance of the queries each run within 1-10 seconds (depending on current server load, as I am querying an enterprise production server/db, this can vary). As I mentioned earlier, the queries run flawlessly sometimes and I have no issues, but at other times I do have issues. Is this a symptom of me querying from a shared production server? Is it preferred to query from a server that has less load? Or am I doing something in my code that could be improved?
const { sql, poolPromise } = require('../db');
// function to get data
const getData = async (req, res) => {
try {
// create query parameters from user request
let id= req.query.id;
// create query from connectionPool
let pool = await poolPromise;
let qry = `
select * from tbl where id = #Id
`
let data = await pool.request()
.input('Id', sql.VarChar(sql.MAX), id)
.query(qry);
// send 200 status and return records
res.status(200);
res.send(data.recordset);
} catch(err) {
console.log('Error:');
console.log(err);
res.sendStatus(500);
}
};
module.exports = { getData };

Using redis in an Express route

I want to simply be able to store a value in a key in one route
/api/foo?redisKey="1" (set value for id=1)
then I want to get the value in another route.
/api/bar?redisKey="1" (get value for id=1)
However, redis is async so you have to wait for it to connect
client.on('connect', function() {
//perform redis operations
});
I'm not sure how to synchronize this in my router.

I am going to assume you're using redis for your client library.
In your express route file, you do not want to create the connection during each request. Instead you will instantiate your redis client outside of the express middleware function, and use it during requests.
Here's a sample app:
var redis = require("redis");
var client = redis.createClient();
var express = require('express')
var app = express()
// GET request
// example: curl "localhost:3000/api/foo?redisKey=1"
app.get('/api/foo', function (req, res) {
var redisKey = req.query.redisKey
client.get(redisKey, function (err, reply) {
if(err){ res.status(400).send(err.getMessage()); return; }
res.status(200).send(reply.toString())
});
})
// for setting, use POST request
// example: curl -X POST "localhost:3000/api/foo?redisKey=1&redisValue=helloWorld"
app.post('/api/foo', function(req, res){
var redisKey = req.query.redisKey,
redisValue = req.query.redisValue
// assuming value is also a string in URL query string
client.set(redisKey, redisValue, function (err, reply){
res.status(200).send(reply.toString())
});
})
app.listen(3000, function () {
console.log('Example app listening on port 3000!')
})

Moongose, expressjs and node-webkit

I'm building an app using node-webkit, based on expressjs and mongoose. I'm new to basically all of this.
I've got a mongoDb hosted online and i'm try to use it in my app, but i'm missing something
I created in model folder db.js, where i connect with the db
var mongoose = require('mongoose');
mongoose.connect('mongodb://user:password#ds012345.mlab.com:port/mydb') //this isn't the real link
then my model, clients.js
var mongoose = require('mongoose');
var Schema = mongoose.Schema;
var clientSchema = new Schema ({
name: String,
//other fields
});
var client = mongoose.model('client', clientSchema);
module.exports = client;
Then, in my app.js
var db = require('./model/db')
I'm also using routes, so in my index.js i got
var client = require('../model/clients')
But i cannot use any function (save, find, ecc.), i can just create models.
I think I'm not connecting in the right way all the modules, i was previously using diskdb and i connected to it in my index.js, but i tried in the same way and it doesn't work anyway.
Also, when i build the app, my mongoose connection status is 2.

Here are a few things:
what is ecc? you should connect to something like this: mongoose.connect('mongodb://localhost:27017/test');
27017 is the default port for MongoDB and test is the name of your database. Also make sure you start mongo server with mongod then run mongo console mongo.
Your field should specify type of the data:
var clientSchema = new Schema ({
name: String,
age: Number
});
So you want to save the document into database:
var client = mongoose.model('client', clientSchema);
var data = {
nome: 'something'
};
var user = new client(data);
user.save(function(err) {
if(err) console.log(err);
});
In your route, you can do something like this to query back and send data back to the req:
var express = require('express');
var router = express.Router();
var clientSchema = require('../models/clientSchema');
router.get('/', function(req, res, next) {
UserSchema.find({} , function(err, data) {
if (err) console.log(err);
res.render('index', {
data: data
});
});
});
module.exports = router;
Hope this help!

How do I use node-mongodb-native to connect to Heroku?

I'm getting really confused over how to connect to MongoLab on Heroku.
To connect using the uri to Heroku, I was trying to follow this example:
http://experiencecraftsmanship.wordpress.com/2012/01/06/heroku-node-js-mongodb-featuring-the-native-driver/
I looked at both his web.js and deep.js.
They both do something like:
connect.createServer(
require( 'connect-jsonrpc' )( contacts )
).listen( port );
But then only the database query in 'contacts' get passed into this server then?
Am I allowed to do multiple connect.createServer for each of my database access method?
The following is part of my code when just connecting to MongoDB locally. I am unsure of how to modify it to connect to MongoLab on Heroku.
Can someone teach me how to modify my code to connect? Or explain some of these concepts? I have no idea why the author of that website I posted used so many callbacks to do a database call, when my approach below seems straightforward enough (I'm new to JavaScript, not good with callbacks).
var app = module.exports = express.createServer(
form({ keepExtensions: true })
);
var Db = require('mongodb').Db;
var Server = require('mongodb').Server;
var client = new Db('blog', new Server('127.0.0.1', 27017, {}));
var posts;
var getAllPosts = function(err, collection) {
collection.find().toArray(function(err, results) {
posts = results;
console.log(results);
client.close();
});
}
app.get('/', function(req, response) {
client.open(function(err, pClient) {
client.collection('posts', getAllPosts);
});
// some code
response.render('layout', { posts: posts, title: 'Raymond', contentPage: 'blog' });
});

You connect to your mongolab database (so you can't create a new "blog" database). process.env.MONGOLAB_URI includes the database name as well. See your mongolab uri:
heroku config | grep MONGOLAB_URI
It looks like: mongodb://heroku_app123456:password#dbh73.mongolab.com:27737/heroku_app123456
On github there is an example how to connect and retrieve data from a mongolab database.

Use "connect" to connect to mongo, instead of defining db, server, client:
var connect = require('connect');
var mongo = require('mongodb');
var database = null;
var mongostr = [YOUR MONGOLAB_URI];
mongo.connect(mongostr, {}, function(error, db)
{
console.log("connected, db: " + db);
database = db;
database.addListener("error", function(error){
console.log("Error connecting to MongoLab");
});
});