What is Couch and Mongo Database | Persisting Mechanism of NOSQL

What is a CouchDB and MongoDB??

 

Before that here is a simple article on what nosql is.

Couchdb is a open-source nosql document oriented database software,It supports as both database and cache.

MongoDB is a document database with the scalability and flexibility that you want with the querying and indexing that you need.

Here's a high-level comparison of SQL Server features/naming as compared to Couchbase:

SQL Server	CouchBase Server	MongoDB Server
Server	Cluster	Server
Database	Bucket	Database
Table	No table concept	Collection
Rows	Document	Document
Column	Field/Value	Field/Value
Primary Key	Document Key	Primary Key

How can we store data into NOSQL??

In a document database(i.e couchbase or mongodb), data is stored as keys and values.
In Couchbase, Bucket contains documents.
In mongodb , Collection contains documents.

Each document has a unique key and a JSON value. There are no foreign keys (or, more accurately, there are no foreign key constraints).

In NOSQL, a shopping cart and the items in it would be represented by a single document.

How does Primary, Foriegn and other relations work is in next chapter