Mongodb general commands

 //cheatsheet

/* key words */

collection = table

/* for databses */

view all databases

-show dbs

create a new or switch databases

-use <databse_name>

view current database

-db

delete database

-db.dropDatabase()

/* for collections */

Show Collections

-show collections

create a collection name 'comments'

-db.createCollection('comments')

delete collections

-db.<collection_name>.drop()

/* mongodb command for rows*/

Show All Rows In a Collection

-db.<collection_name>.find()

-db.<collection_name>.find().pretty() //for preetyfied view

-db.<collection_name>.findOne() // for finding 1st row

Insert One Rows

-db.<collection_name>.insert({'name':'Gyanendra','lang':'javaScript','age':'24'})

Insert Many Rows

-db.<collection_name>.insertMany([{'name':'Gyanendra','lang':'javaScript','age':'24'},{'name':'Gyanendra','lang':'javaScript','age':'24'},{'name':'Arvind','lang':'javaScript','age':'24'},])

Search In a Mongodb Database

-db.<collection_name>.find({'name':'Arvind'})

Limit The Number of Rows In Output

-db.<collection_name>.find().limit(10)

Count Rows

-db.<collection_name>.count()

or 

-db.<collection_namee>.limit(3).count()

//these two has same output because limit only limits the output data not the whole data