Upload Excel to MongoDB

index.js

const fs = require('fs');
const multer = require('multer');
const express = require('express');

let MongoClient = require('mongodb').MongoClient;
let url = 'mongodb://localhost:27017/';

const excelToJson = require('convert-excel-to-json');

const app = express();

global.__basedir = __dirname;

// -> Multer Upload Storage
const storage = multer.diskStorage({
  destination: (req, file, cb) => {
    cb(null, __basedir + '/uploads/');
  },
  filename: (req, file, cb) => {
    cb(null, file.fieldname + '-' + Date.now() + '-' + file.originalname);
  },
});

const upload = multer({ storage: storage });

// -> Express Upload RestAPIs
app.post('/api/uploadfile', upload.single('uploadfile'), (req, res) => {
  importExcelData2MongoDB(__basedir + '/uploads/' + req.file.filename);
  res.json({
    msg: 'File uploaded/import successfully!',
    file: req.file,
  });
});

// -> Import Excel File to MongoDB database
function importExcelData2MongoDB(filePath) {
  // -> Read Excel File to Json Data
  const excelData = excelToJson({
    sourceFile: filePath,
    sheets: [
      {
        // Excel Sheet Name
        name: 'Customers',

        // Header Row -> be skipped and will not be present at our result object.
        header: {
          rows: 1,
        },

        // Mapping columns to keys
        columnToKey: {
          A: '_id',
          B: 'name',
          C: 'address',
          D: 'age',
        },
      },
    ],
  });

  // -> Log Excel Data to Console
  console.log(excelData);

  /**
    { 
        Customers:
        [ 
            { _id: 1, name: 'Jack Smith', address: 'Massachusetts', age: 23 },
            { _id: 2, name: 'Adam Johnson', address: 'New York', age: 27 },
            { _id: 3, name: 'Katherin Carter', address: 'Washington DC', age: 26 },
            { _id: 4, name: 'Jack London', address: 'Nevada', age: 33 },
            { _id: 5, name: 'Jason Bourne', address: 'California', age: 36 } 
        ] 
    }
    */

  // Insert Json-Object to MongoDB
  MongoClient.connect(url, { useNewUrlParser: true }, (err, db) => {
    if (err) throw err;
    let dbo = db.db('gkzdb');
    dbo.collection('customers').insertMany(excelData.Customers, (err, res) => {
      if (err) throw err;
      console.log('Number of documents inserted: ' + res.insertedCount);
      /**
                Number of documents inserted: 5
            */
      db.close();
    });
  });

  fs.unlinkSync(filePath);
}

// Create a Server
let server = app.listen(8080, function () {
  let host = server.address().address;
  let port = server.address().port;

  console.log('App listening at http://%s:%s', host, port);
});