code example for CSV Importer with Node

Co-authored-by: Arpendu Kumar Garai <Arpendu.KumarGarai@microfocus.com>

nodejs/node-csv-importer/server/controllers/csv.controller.js

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+import Employee from '../models/employee.model.js';
+import { createReadStream } from 'fs';
+import { parse } from 'fast-csv';
+import { Parser as CsvParser } from 'json2csv';
+
+const upload = async (req, res) => {
+  try {
+    if (req.file == undefined) {
+      return res.status(400).send("Please upload a CSV file!");
+    }
+
+    let employees = [];
+    let path = "./resources/static/assets/uploads/" + req.file.filename;
+
+    createReadStream(path)
+      .pipe(parse({ headers: true }))
+      .on("error", (error) => {
+        throw error.message;
+      })
+      .on("data", (row) => {
+        employees.push(row);
+      })
+      .on("end", () => {
+        Employee.bulkCreate(employees)
+          .then(() => {
+            res.status(200).send({
+              message: "The file: "
+               + req.file.originalname
+               + " got uploaded successfully!!",
+            });
+          })
+          .catch((error) => {
+            res.status(500).send({
+              message: "Couldn't import data into database!",
+              error: error.message,
+            });
+          });
+      });
+  } catch (error) {
+    console.log(error);
+    res.status(500).send({
+      message: "Failed to upload the file: " + req.file.originalname,
+    });
+  }
+};
+
+const download = (_req, res) => {
+  Employee.findAll().then((objs) => {
+    let employees = [];
+
+    objs.forEach((obj) => {
+      const { id, name, email,
+        username, dob, company,
+        address, location, salary,
+        about, role } = obj;
+      employees.push({ id, name, email,
+        username, dob, company,
+        address, location, salary,
+        about, role });
+    });
+
+    const csvFields = ['id', 'name', 'email',
+                     'username', 'dob', 'company',
+                     'address', 'location', 'salary',
+                     'about', 'role'];
+    const csvParser = new CsvParser({ csvFields });
+    const csvData = csvParser.parse(employees);
+
+    res.setHeader('Content-Type', 'text/csv');
+    res.setHeader('Content-Disposition', 'attachment; filename=employees.csv');
+
+    res.status(200).end(csvData);
+  });
+};
+
+export default {
+  upload,
+  download,
+};