MongoDB, the most popular NoSQL database, is an open-source document-oriented database. The term ‘NoSQL’ means ‘non-relational’. It means that MongoDB isn’t based on the table-like relational database structure but provides an altogether different mechanism for storage and retrieval of data. This format of storage is called BSON ( similar to JSON format). Refer (this) article.
MongoDB module: This module of Node.js is used for connecting the MongoDB database as well as used for manipulating the collections and databases in MongoDB. The mongodb.connect() method is used for connecting the MongoDB database which is running on a particular server on your machine. (Refer to this article). We can also use promises, in this method in resolve the object contains all the methods and properties required for collection manipulation and in reject the error occurs during connection.
Installing module:
node install mongodb
Project Structure:
Running the server on Local IP: data is folder name
mongod --dbpath=data --bind_ip 127.0.0.1
MongoDB Database:
Database:GFG Collection:GFGcollections
Index.js
1. Fetching single document of GFGcollections
const MongoClient = require( "mongodb" );
const databasename = "GFG" ; // Database name
MongoClient.connect(url).then((client) => { const connect = client.db(databasename);
// Connect to collection
const collection = connect
.collection( "GFGcollections" );
// Fetching the records having
// name as saini
collection.find({ "name" : "saini" })
.toArray().then((ans) => {
console.log(ans);
});
}). catch ((err) => {
// Printing the error message
console.log(err.Message);
}) |
Output:
2. Fetching all documents of the GFGcollections
const MongoClient = require( "mongodb" );
const databasename = "GFG" ; // Database name
MongoClient.connect(url).then((client) => { const connect = client.db(databasename);
// Connect to collection
const collection = connect
.collection( "GFGcollections" );
collection.find({}).toArray().then((ans) => {
console.log(ans);
});
}). catch ((err) => {
// Printing the error message
console.log(err.Message);
}) |
Output: