Retrieving Mongo Array Value into Flat Files

Assume that you have a collection with below document structure and you need to export the values in readable csv format. We can achieve this easily by using MONGOEXPORT function as stated below: 

>mongoexport --type=csv -d school -c students -f _id, name, scores.0.type, scores.0.score -o export.csv

The above command will create a export.csv file with following format:

_id	scores.0.type	scores.0.score	name
19	exam	44.51211102	Gisela Levin
20	exam	42.174398	Tressa Schwing
21	exam	46.22894763	Rosana Vales
22	exam	75.04996548	Margart Vitello

In case you want to apply any query filter, then you can use -q option in the command:
>mongoexport --type=csv -d school -c students -f _id, name, scores.0.type, scores.0.score  -q {_id:{$gte:19}} -o export.csv

Here I retrieve student data with _id >= 19.

Restoring dump in Mongo DB

Use mongorestore command to restore dump in mongo DB.

C:Users\******> mongorestore --db m101test D:\WorkArea\Mongo\chapter_1_introduction.e9b31121cdb8\homework_1_1\hw1-1\dump\m101

How to change DB path of Mongo database in Windows?

Apply below code in command prompt to change DB path of  Mongo database:

C:\Program Files\MongoDB\Server\3.2\bin> mongod.exe --dbpath <folderlocation> (example D:\mongo\data)

Installing Numpy, Sci-py, Cython, and Pandas in Ubuntu machine

Numpy, Sci-py, Cython, and Pandas are the important pacjages used in python data analysis. In order to perform operations using these packages we need to install them in to the system. Execute the following scripts in terminal:

sudo apt-get install python-numpy
sudo apt-get install cython
sudo apt-get install python-scipy
sudo apt-get install python-pandas