Basic commands in mongodb

Lets continue with Basic commands in mongodb :

• db : This command returns the name of connected database.

C:\Users\Nagendra>mongo 2016-03-28T21:35:56.979+0530 I CONTROL  Hotfix KB2731284 or later update is not installed, will zero-out data files MongoDB shell version: 3.0.10 connecting to: test > > db test >

• show databases : This command returns the list of all databases on the server.

> show databases local  0.078GB pcat   0.078GB test   0.078GB >

• show collections : This command returns the list of all collections in current database.

> show collections names system.indexes >

• use <database_name> : Used to switch between database. It will create new database if not already present.

> db test > use pcat switched to db pcat >  > db pcat >  > show collections product products products_bak system.indexes >

• help : returns commands information

> help         db.help()                       help on db methods         db.mycoll.help()          help on collection methods         sh.help()                       sharding helpers         rs.help()                        replica set helpers         help admin                    administrative help         help connect                 connecting to a db help         help keys                       key shortcuts         help misc                       misc things to know         help mr                          mapreduce         show dbs                        show database names         show collections           show collections in current database         show users                     show users in current database         show profile                  show most recent system.profile entries with time >= 1ms         show logs                       show the accessible logger names         show log [name]           prints out the last segment of log in memory, 'global' is default         use <db_name>             set current database         db.foo.find()                   list objects in collection foo         db.foo.find( { a : 1 } )    list objects in foo where a == 1         it                                       result of the last line evaluated; use to further iterate         exit                                  quit the mongo shell >

What is JSON , Insert & find queries ? ...To be continued.