Node JS and MongoDB
Mostly all modern-day web applications have some sort of data storage system at the backend. For example, if you take the case of a web shopping application, data such as the price of an item would be stored in the database.
The Node js framework can work with databases with both relational (such as Oracle and MS SQL Server) and non-relational databases (such as MongoDB).
What is MongoDB?
MongoDB is a cross-platform (runs on multiple operating systems), document-oriented database management system (DBMS). MongoDB is also a NoSQL database, which means it does not use SQL to perform operations on a database.
MongoDB uses documents that are in JSON-like format, known as BSON, which is the binary encoding of JSON.
It’s developed as an open-source project by MongoDB Inc. under the Server Side Public License.
Node and MongoDB work very-well together, in part because Mongo uses a JavaScript engine built into the database since JavaScript is good at handling JSON objects.
Compared to other databases, such as MySQL, MongoDB is fast for storing certain types of data and can be automatically scaled. It’s very simple to implement and get running.
With Mongo being a NoSQL database, it has its own way of storing data. Here are some of the constructs that make up the database structure:
- Database: The container that holds a set of collections.
- Collection: A set of documents. This is similar to a table in an SQL database. However, unlike an SQL database, a collection does not have a set structure or pre-configured data types.
- Documents: A JSON-like object. This is similar to a row in an SQL database. A JSON object may also contain child objects, an array, etc.
- _id: Mandatory unique field in every document. It separates one document from another, so we can identify each document independently. If this value is not provided, MongoDB automatically assigns a random value for the field.
CRUD Operation in MongoDB
CRUD stands for ” create, read, update, and delete”. Crud operations are used to create, read, update, and delete any documents. For performing any crud operation in MongoDB, you need a database and a collection. First. create a database and then create a collection. First of all in your present working directory execute this command .
npm install mondodb --save
Step 1 – Create a database
Create a .js page(createdatabase.js) and now write the code: (createdatabase.js)
const { MongoClient } = require("mongodb");
const uri = "mongodb://127.0.0.1:27017/";
const client = new MongoClient(uri, { useNewUrlParser: true, useUnifiedTopology: true });
async function run() {
try {
const database = client.db('navigcollection');
console.log("Database Created !!!")
} finally {
// Ensures that the client will close when you finish/error
await client.close();
}
}
run().catch(console.dir);
Now run this file :
node createDatabase.js
After the run, you should see that your database looks like this:
Now go to the mongodb compass and refresh the databases. after refreshing the database you see there is no database in databases.
Because an empty database doesn’t show in the database list, to view the database we need to again create a collection in your database. After creating collection your database is shown in the databases list.
Step 2 – Create collection in database – Create a .js file createcollection.js and write this code.
const { MongoClient } = require("mongodb");
// Replace the uri string with your connection string.
const uri = "mongodb://127.0.0.1:27017/";
const client = new MongoClient(uri, { useNewUrlParser: true, useUnifiedTopology: true });
async function run() {
try {
const database = client.db('navigcollection');
await database.createCollection("pract3", function (error, response) {
if (error) {
throw error;
}
});
console.log("collection is created.....")
} finally {
// Ensures that the client will close when you finish/error
await client.close();
}
}
run().catch(console.dir);
Now run this :
node createcollection.js
After running, the output will look like:
Now go to the database and refresh databases. After refreshing, the output will look like:
Step 3 – Insert record in database – Now insert a record in the collection, to insert a record in the database create a new file insert1docu.js and write this code.
const { MongoClient } = require("mongodb");
// Replace the uri string with your connection string.
const uri = "mongodb://127.0.0.1:27017/";
const client = new MongoClient(uri, { useNewUrlParser: true, useUnifiedTopology: true });
async function run() {
try {
var nodetestDB = client.db("navigcollection"); //here
var customersCollection = nodetestDB.collection("pract");
var customer = { _id: 111, name: "Santosh Kumar", address: "B-222, Sector-19, NOIDA", orderdata: "Arrow Shirt" };
await customersCollection.insertOne(customer, function (error, response) {
if (error) { throw error; }
});
console.log("1 document inserted");
} finally {
// Ensures that the client will close when you finish/error
await client.close();
}
}
run().catch(console.dir);
Now run this program :
node insert1docu.js
Output will look like:
Then open database and refresh collection:
Step 3 – Insert Many records : create a js file createmanydocu.js and write this code:
var mongodb = require('mongodb');
var MongoClient = mongodb.MongoClient;
var url = 'mongodb://localhost:27017/';
MongoClient.connect(url, function(error, databases) {
if (error) {
const { MongoClient } = require("mongodb");
// Replace the uri string with your connection string.
const uri = "mongodb://127.0.0.1:27017/";
const client = new MongoClient(uri, { useNewUrlParser: true, useUnifiedTopology: true });
async function run() {
try {
var nodetestDB = client.db("navigcollection"); //here
var pract = [
{ _id: 11, name: "Chaman Gautam", address: "Harvansh nagar Ghaziabad", orderdata: "Jeans" },
{ _id: 12, name: "Shivani", address: "Harvansh nagar Ghaziabad", orderdata: "Jeans" },
{ _id: 13, name: "Menu", address: "Harvansh nagar Ghaziabad", orderdata: "Top" },
{ _id: 14, name: "Brajbala", address: "Harvansh nagar Ghaziabad", orderdata: "Dinig table" },
{ _id: 15, name: "Ramsaran", address: "Harvansh nagar Ghaziabad", orderdata: "Washing machine" },
{ _id: 16, name: "Dheeraj", address: "Harvansh nagar Ghaziabad", orderdata: "Jeans" }
]
var customersCollection = nodetestDB.collection("pract");
await customersCollection.insertMany(pract, function (error, response) {
if (error) { throw error; }
});
console.log("Many document inserted");
} finally {
// Ensures that the client will close when you finish/error
await client.close();
}
}
run().catch(console.dir);
Now run this file :
node createmanydocu.js
Output will look like:
Now go to the database and refresh the database, the database will look like this:
Step 5 – Find record from database – Find 1 record from collection
Now creata a .js page find1docu.js and write this code:
const { MongoClient } = require("mongodb");
// Replace the uri string with your connection string.
const uri = "mongodb://127.0.0.1:27017/";
const client = new MongoClient(uri, { useNewUrlParser: true, useUnifiedTopology: true });
async function run() {
try {
var nodetestDB = client.db("navigcollection"); //here
var customersCollection = nodetestDB.collection("pract");
const result = await customersCollection.findOne({ name: 'Shivani' }, function(err) {
if (err) throw err;
})
console.log("one record is find now....." + result.name + ", " + result.address + ", " + result.orderdata);
} finally {
// Ensures that the client will close when you finish/error
await client.close();
}
}
run().catch(console.dir);
Now run this :
node find1docu.js
Output will look like this:
find many record from collection – Now, create a new .js page findmanydocu.js and write the following code:
const { MongoClient } = require("mongodb");
// Replace the uri string with your connection string.
const uri = "mongodb://127.0.0.1:27017/";
const client = new MongoClient(uri, { useNewUrlParser: true, useUnifiedTopology: true });
async function run() {
try {
var nodetestDB = client.db("navigcollection"); //here
var customersCollection = nodetestDB.collection("pract");
const result = await customersCollection.find({}).toArray(function (err) {
if (err) throw err;
})
for (i = 0; i < result.length; i++) {
let pract = result[i];
console.log(pract.name + ", " + pract.address + ", " + pract.orderdata);
}
} finally {
// Ensures that the client will close when you finish/error
await client.close();
}
}
run().catch(console.dir);
Now compile this program in terminal and write command for the compile:
node findmanydocu.js
After running, the output will look like,
Step 6 – update record in collection
Update one record from collection
Now you need to create 1 new .js file updateone.js and write this code:
const { MongoClient } = require("mongodb");
// Replace the uri string with your connection string.
const uri = "mongodb://127.0.0.1:27017/";
const client = new MongoClient(uri, { useNewUrlParser: true, useUnifiedTopology: true });
async function run() {
try {
var nodetestDB = client.db("navigcollection"); //here
var customersCollection = nodetestDB.collection("pract");
var whereClause = { name: /Chaman Gautam/ };
var newvalues = { $set: { name: "Lucky Gautam" } };
const result = await customersCollection.updateOne(whereClause,newvalues, function(err) {
if (err) throw err;
})
console.log("document updated");
} finally {
// Ensures that the client will close when you finish/error
await client.close();
}
}
run().catch(console.dir);
Now compile this program in terminal and write the command for compile:
node updateone.js
After running this command output will show in terminal like this:
The database will show like this without refresh database:
After refresh, the database output will look like this:
Now update many records from collection
For update records in your database collection, you need to create a new .js file updatemany.js and write this code
const { MongoClient } = require("mongodb");
// Replace the uri string with your connection string.
const uri = "mongodb://127.0.0.1:27017/";
const client = new MongoClient(uri, { useNewUrlParser: true, useUnifiedTopology: true });
async function run() {
try {
var nodetestDB = client.db("navigcollection"); //here
var customersCollection = nodetestDB.collection("pract");
var whereClause = { address: /Harvansh nagar/ };
var newvalues = { $set: { name: "Shivani" } };
const result = await customersCollection.updateMany(whereClause,newvalues, function(err) {
if (err) throw err;
})
console.log("Multiple Documents updated");
} finally {
// Ensures that the client will close when you finish/error
await client.close();
}
}
run().catch(console.dir);
Now you need to compile this file in terminal using command
node updatemany.js
After running this command output will be shown in the terminal like this
Now go to the database
Before refresh database show like this:
After refresh, the database output will look like this now see the address in this collection address value will be changed
Step 7 – now delete operation
delete one record from collection
Now you need to create a new .js file deleteone.js and write this code
const { MongoClient } = require("mongodb");
// Replace the uri string with your connection string.
const uri = "mongodb://127.0.0.1:27017/";
const client = new MongoClient(uri, { useNewUrlParser: true, useUnifiedTopology: true });
async function run() {
try {
var nodetestDB = client.db("navigcollection"); //here
var customersCollection = nodetestDB.collection("pract");
var deleteQuery = { name: 'Shivani' };
const result = await customersCollection.deleteOne(deleteQuery, function(err) {
if (err) throw err;
})
console.log("1 document deleted");
} finally {
// Ensures that the client will close when you finish/error
await client.close();
}
}
run().catch(console.dir);
Now compile this program in terminal and write command for compile,
node deleteone.js
After compiling, the code output will be shown in the terminal like this:
Now go the database and check the database collection
Before refreshing the database output, it’s shown like this
After a refresh, the database output will be shown like this:
Now you can see there is six records with the name of Shivani
Delete many records from database
Now you need again create a .js file deletemany.js
const { MongoClient } = require("mongodb");
// Replace the uri string with your connection string.
const uri = "mongodb://127.0.0.1:27017/";
const client = new MongoClient(uri, { useNewUrlParser: true, useUnifiedTopology: true });
async function run() {
try {
var nodetestDB = client.db("navigcollection"); //here
var customersCollection = nodetestDB.collection("pract");
var deleteQuery = { name: 'Shivani' };
const result = await customersCollection.deleteMany(deleteQuery, function(err) {
if (err) throw err;
})
console.log("Many documents deleted");
} finally {
// Ensures that the client will close when you finish/error
await client.close();
}
}
run().catch(console.dir);
Now you need to compile this code in terminal using command
node deletemany.js
After compiling this code output is shown in terminal like this:
Now go to the database and check database
Before refresh database, the database will be shown like this
After refresh database is shown like this:
Now you will see that the database has a collection but only one record in the collection
Now the CRUD operation in MongoDB using Node.js and VS code is complete.