Delete Row In MongoDB

To delete a document in a MongoDB collection using Mongoose.

we can use the "deleteOne()" or "deleteMany()" method provided by Mongoose models.

Define a Mongoose Model:

First, define a Mongoose model that corresponds to the collection you want to delete documents from.

Example:

const mongoose = require('mongoose');

const employeeSchema = new mongoose.Schema({
  name: String,
  email: String,
  department: String,
  age: Number
});

// Define a model based on the schema
const Employee = mongoose.model('Employee', employeeSchema);

module.exports = Employee;

Use the "deleteOne()" or "deleteMany()" Method:

Now, We can use the "deleteOne()" or "deleteMany()" method provided by the "EmployeeModel" model to delete documents from the "Employee" collection.

These methods take a filter object to specify the documents to delete.

deleteOne():

We can use the "deleteOne()" method to delete specific a document that matches the filter criteria.

Example:

const EmployeeModel = require("./employeeModel");

async function deleteEmployee(req, res) {
  // Delete Employee with a specific name and age.
  // For Demo Purpose we are updating directly with GET HTTP Method.

 // we use DELETE HTTP Method to delete document.
  return await EmployeeModel.deleteOne({ name: 'Alice Collin', age: 20 })
  .then((emp) => {
    console.log('Deleted Employee Successfully:', emp);
    res.end(JSON.stringify(emp));
  })
  .catch((err) => {
    console.error('Error while Deleting employee:', err);
    res.end(JSON.stringify(err));
  });
}

module.exports = { deleteEmployee };

deleteMany():

We can also use the "deleteMany()" method to delete multiple documents that match the filter criteria.

Example:

const EmployeeModel = require("./employeeModel");

async function deleteEmployees(req, res) {
 // Delete All Employees which match the criteria in Employee Collection
 return await EmployeeModel.deleteMany({ department: "Finance"})
  .then((employees) => {
    console.log('All Employees Documents deleted successfully:', employees);
    res.end(JSON.stringify(employees));
  })
  .catch((err) => {
    console.error('Error while deleting Employees:', err);
    res.end(JSON.stringify(err));
  });

module.exports = { deleteEmployees };

Define Routing in `server.js`:

import the `deleteEmployee` and `deleteEmployees` functions from the `employeeController` file and place them inside `/delete-employee` and `delete-employees` conditions respectively.

Example:

let http = require("http");
const url = require("url");

const dbConnection = require("./db");
const { deleteEmployee, deleteEmployees } = require("./employeeController");

http
  .createServer((req, res) => {
    res.writeHead(200, { "Content-Type": "text/html" });

    // Parse the requested URL
    const parsedUrl = url.parse(req.url, true);
    const { pathname } = parsedUrl;

    if (pathname === "/delete-employee") {
      deleteEmployee(req, res);
    } else if (pathname === "/delete-employees") {
      deleteEmployees(req, res);
    } else {
      res.end("Server Listening...");
    }

  })
  .listen(3002, () => {
    console.log(`server listening on port 3002!`);
    dbConnection();
  });

To delete employee data from Collection, we often use the `DELETE` HTTP Method to delete data from Collections, but for testing, if you try to hit GET Request on `http://localhost:3002/delete-employee` and `http://localhost:3002/delete-employees` from a web browser. it will return the deleted document count from the Collection if it exists.

<-- Update Row

Sorting Data -->