NoSQL

A NoSQL database refers to a non-relational database that is short for non SQL and Not only SQL. It is a data-storing and data-retrieving system.

Understanding NoSQL | MongoDB

Similar to relational databases (such as MySQL and MSSQL), MongoDB consists of databases, tables, fields but with different names where

• Collections are similar to tables or views in MySQL and MSSQL.

• Documents are similar to rows or records in MySQL and MSSQL.

• Fields are similar to columns in MySQL and MSSQL.

Brief look at operators between MongoDB and MySQL:

$and equivalent to AND in MySQL
$or equivalent to OR in MySQL
$eq equivalent to = in MySQL

Query and Projection Operatorsmongodb

Interacting with a MongoDB server

• show databases : list all the databases

• use <database> : to connect to a database

• db.createCollection() : create new collections

• db.getCollectionNames(); : show all available collections within the database

• db.users.insert({id:"1", username: "admin", email: "[email protected]", password: "idk2021!"}) : insert data into users collection

• db.users.find() : show available documents within the collection

• db.users.update({id:"2"}, {$set: {username: "tryhackme"}}); || db.<collection>.update : to update a document

• db.users.remove() : remove a document

• db.users.drop() : drop a collection