Create a reusable database connection for MongoDB with NodeJS

<form action="/new" method="post">
 
  <input name="title" type="text">
  <input name="description" type="text">
  <button type="submit">Submit Form</button>
 
</form>

npm install heroku-ssl-redirect

var mongoose = require('mongoose');
var Schema = mongoose.Schema;

const exampleSchema = new Schema({
    title: { type: String , required: true},
    content: [{type: String}]
});


var Example = mongoose.model('Example', exampleSchema);
module.exports = Example;

router.post('/:id/edit', auth.requireLogin, (req, res, next) => {
  Post.findByIdAndUpdate(req.params.id, req.body, function(err, post) {
    if(err) { console.error(err) };

     res.redirect(`/`+req.params.id);
  });
});

var express = require("express");
var app = express();
const session = require('express-session');
var MemcachedStore = require('connect-memjs')(session);

// configure sessions
var store = new MemcachedStore({servers: [process.env.MEMCACHEDCLOUD_SERVERS], username: process.env.MEMCACHEDCLOUD_USERNAME, password: process.env.MEMCACHEDCLOUD_PASSWORD});
app.use(session({ secret: 'keyboard cat',
   resave: true,
   saveUninitialized: true,
   cookie: { secure: true }, 
   store: store
}))

var mongoose = require('mongoose');
var Schema = mongoose.Schema;
var slug = require('mongoose-slug-generator');

mongoose.plugin(slug);

const pageSchema = new Schema({
    title: { type: String , required: true},
    slug: { type: String, slug: "title" }
});

var Page = mongoose.model('Page', pageSchema);
module.exports = Page;

function processSQLFile(fileName) {

  // Extract SQL queries from files. Assumes no ';' in the fileNames
  var queries = fs.readFileSync(fileName).toString()
    .replace(/(\r\n|\n|\r)/gm," ") // remove newlines
    .replace(/\s+/g, ' ') // excess white space
    .split(";") // split into all statements
    .map(Function.prototype.call, String.prototype.trim)
    .filter(function(el) {return el.length != 0}); // remove any empty ones

  // Execute each SQL query sequentially
  queries.forEach(function(query) {
    batch.push(function(done) {
      if (query.indexOf("COPY") === 0) { // COPY - needs special treatment
        var regexp = /COPY\ (.*)\ FROM\ (.*)\ DELIMITERS/gmi;
        var matches = regexp.exec(query);
        var table = matches[1];
        var fileName = matches[2];
        var copyString = "COPY " + table + " FROM STDIN DELIMITERS ',' CSV HEADER";
        var stream = client.copyFrom(copyString);
        stream.on('close', function () {
          done();
        });
        var csvFile = __dirname + '/' + fileName;
        var str = fs.readFileSync(csvFile);
        stream.write(str);
        stream.end();
      } else { // Other queries don't need special treatment
        client.query(query, function(result) {
          done();
        });
      }
    });
  });
}

const comparePassword = async (password, hash) => {
    try {
        // Compare password
        return await bcrypt.compare(password, hash);
    } catch (error) {
        console.log(error);
    }

    // Return false if error
    return false;
};

//use case
(async () => {
    // Hash fetched from DB
    const hash = `$2b$10$5ysgXZUJi7MkJWhEhFcZTObGe18G1G.0rnXkewEtXq6ebVx1qpjYW`;

    // Check if password is correct
    const isValidPass = await comparePassword('123456', hash);

    // Print validation status
    console.log(`Password is ${!isValidPass ? 'not' : ''} valid!`);
    // => Password is valid!
})();

db.customers.updateMany({},
  [{ $set : { m : {$arrayElemAt:[{ $split: ["$customerName", " "] },0]}} }],

);

# Open the terminal in the app dyno in Heroku

heroku run bash

 

# We may then run the seed file

node bin/seed.js

const songs[];
const results;

for (var i, i++, i<songs.length){
    if(song[i].artist == "Drake"){
      result.push(songs[i]);
    };

// OR

const songs [];
const result = songs.filter ( song => song.artist == "Drake");

$.ajax({
  type: "POST",
  url: url,
  data: data,
  success: function (result) {
       alert("The result is "+result);
	}
});
                                

                                var app = express()
var sess = {
  secret: 'keyboard cat',
  cookie: {}
}
 
if (app.get('env') === 'production') {
  app.set('trust proxy', 1) // trust first proxy
  sess.cookie.secure = true // serve secure cookies
}
 
app.use(session(sess))