Node.js MongoDB

• Node.js can be used in database applications.
• One of the most popular NoSQL database is MongoDB.

Creating a Database(table)

var MongoClient = require('mongodb').MongoClient;
var url = "mongodb://localhost:27017/mydb";

MongoClient.connect(url, function(err, db) {
  if (err) throw err;
  console.log("Database created!");
  db.close();
});

Save the code above in a file called "demo_create_mongo_db.js" and run the file:

C:\Users\Your Name>node demo_create_mongo_db.js 

Which will give you this result:

Database created!

Creating a Table

 var MongoClient = require('mongodb').MongoClient;
var url = "mongodb://localhost:27017/mydb";

MongoClient.connect(url, function(err, db) {
  if (err) throw err;
  db.createCollection("customers", function(err, res) {
    if (err) throw err;
    console.log("Table created!");
    db.close();
  });
});

Save the code above in a file called "demo_create_mongo_table.js" and run the file:

C:\Users\Your Name>node demo_create_mongo_table.js 

Which will give you this result:

Table created!

Insert Into Tabe

var MongoClient = require('mongodb').MongoClient;
var url = "mongodb://localhost:27017/mydb";

MongoClient.connect(url, function(err, db) {
  if (err) throw err;
  var myobj = { name: "Company Inc", address: "Highway 37" };
  db.collection("customers").insertOne(myobj, function(err, res) {
    if (err) throw err;
    console.log("1 record inserted");
    db.close();
  });
}); 

 

var MongoClient = require('mongodb').MongoClient;
var url = "mongodb://localhost:27017/mydb";

MongoClient.connect(url, function(err, db) {
  if (err) throw err;
  var myobj = [
    { name: 'John', address: 'Highway 71'},
    { name: 'Peter', address: 'Lowstreet 4'},
    { name: 'Amy', address: 'Apple st 652'},
    { name: 'Hannah', address: 'Mountain 21'},
    { name: 'Michael', address: 'Valley 345'},
    { name: 'Sandy', address: 'Ocean blvd 2'},
    { name: 'Betty', address: 'Green Grass 1'},
    { name: 'Richard', address: 'Sky st 331'},
    { name: 'Susan', address: 'One way 98'},
    { name: 'Vicky', address: 'Yellow Garden 2'},
    { name: 'Ben', address: 'Park Lane 38'},
    { name: 'William', address: 'Central st 954'},
    { name: 'Chuck', address: 'Main Road 989'},
    { name: 'Viola', address: 'Sideway 1633'}
  ];
  db.collection("customers").insert(myobj, function(err, res) {
    if (err) throw err;
    console.log("Number of records inserted: " + res.insertedCount);
    db.close();
  });
}); 

  Save the code above in a file called "demo_mongodb_insert.js" and run the file:

C:\Users\Your Name>node demo_mongodb_insert.js 

Which will give you this result:

1 record inserted

Select One from form

var http = require('http');
var MongoClient = require('mongodb').MongoClient;
var url = "mongodb://localhost:27017/mydb";

MongoClient.connect(url, function(err, db) {
  if (err) throw err;
  db.collection("customers").findOne({}, function(err, result) {
    if (err) throw err;
    console.log(result.name);
    db.close();
  });
}); 

Save the code above in a file called "demo_mongodb_findone.js" and run the file:

C:\Users\Your Name>node demo_mongodb_findone.js 

Which will give you this result:

Company Inc.

Select All

var MongoClient = require('mongodb').MongoClient;
var url = "mongodb://localhost:27017/mydb";

MongoClient.connect(url, function(err, db) {
  if (err) throw err;
  db.collection("customers").find({}).toArray(function(err, result) {
    if (err) throw err;
    console.log(result);
    db.close();
  });
});

Filter the Result

var http = require('http');
var MongoClient = require('mongodb').MongoClient;
var url = "mongodb://localhost:27017/mydb";

MongoClient.connect(url, function(err, db) {
  if (err) throw err;
  var query = { address: "Park Lane 38" };
  db.collection("customers").find(query).toArray(function(err, result) {
    if (err) throw err;
    console.log(result);
    db.close();
  });
});

Save the code above in a file called "demo_mongodb_query.js" and run the file:

C:\Users\Your Name>node demo_mongodb_query.js 

Which will give you this result:

[
  { _id: 58fdbf5c0ef8a50b4cdd9a8e , name: 'Ben', address: 'Park Lane 38' }
]

Introduction to node js

 What is Node.js?

• Node.js is an open source server framework
• Node.js is free
• Node.js runs on various platforms (Windows, Linux, Unix, Mac OS X, etc.)
• Node.js uses JavaScript on the server

Why Node.js?

1. Sends the task to the computer's file system.
2. Ready to handle the next request.
3. When the file system has opened and read the file, the server returns the content to the client.

Node.js eliminates the waiting, and simply continues with the next request.
Node.js runs single-threaded, non-blocking, asynchronously programming, which is very memory efficient.

What Can Node.js Do?

• Node.js can generate dynamic page content
• Node.js can create, open, read, write, delete, and close files on the server
• Node.js can collect form data
• Node.js can add, delete, modify data in your database

What is a Node.js File?

• Node.js files contain tasks that will be executed on certain events
• A typical event is someone trying to access a port on the server
• Node.js files must be initiated on the server before having any effect
• Node.js files have extension ".js"