MongoDB’s find() method selects documents from a collection or view and returns a cursor to those documents. There are two parameters in this formula: query and projection.
Query – This is an optional parameter that specifies the criteria for selection. In simple terms, a query is what you want to search for within a collection.
Projection – This is an optional parameter that specifies what should be returned if the query criteria are satisfied. In simple terms, it is a type of decision-making that is based on a set of criteria.
MongoDB’s Flexible Schema
A NoSQL database, which stands for “not only SQL,” is a way of storing and retrieving data that is different from relational databases’ traditional table structures (RDBMS).
When storing large amounts of unstructured data with changing schemas, NoSQL databases are indeed a better option than RDBMS. Horizontal scaling properties of NoSQL databases allow them to store and process large amounts of data.
MongoDB is one of the most widely used open-source NoSQL document databases. MongoDB is known as a ‘schemaless’ database because it does not impose a specific structure on documents in a collection. MongoDB is compatible with a number of popular programming languages. It also offers a high level of operational flexibility because it scales well horizontally, allowing data to be spread or ‘sharded’ across multiple commodity servers with the ability to add more servers as needed. MongoDB can be run on a variety of platforms, including developer laptops, private clouds, and public clouds.