How to import and export a MongoDB database on Ubuntu 20.04?

Overview

MongoDB database is created and managed by MongoDB. It is widely recognized as a NoSQL database system renowned for its scalability, robustness, dependability, and user-friendly nature.

This tutorial aims to demonstrate the process of importing and exporting MongoDB databases, emphasizing that these operations involve handling data in format that humans can easily read and is compatible with various other software applications.

Prerequisites

There are certain prerequisites that need to be met before you begin:

• A server running Ubuntu version 20.04 with sudo access and a UFW firewall is turned on.

• Ensure that MongoDB is installed.

• Comprehending the disparities between JSON data and BSON data.

Get Started

Step 1 - Import data into MongoDB

• For importing data into MongoDB, let's use a widely used MongoDB database containing restaurant's information. You can download this database in the .json format by running the following wget command:

wget https://raw.githubusercontent.com/mongodb/docs-assets/primer-dataset/primer-dataset.json

• Once it is downloaded, you will get a file named primer-dataset located in current directory. To import data from the downloaded file into newly created database, newdb and in a collection named restaurants, employ the following command:

sudo mongoimport --db newdb --collection restaurants --file primer-dataset.json

• To confirm the successful import, establish a connection to newdb database:

sudo mongo newdb

• Determine the number of documents in restaurants collection by executing the following command:

db.restaurants.count()

• Retrieve the initial document from restaurants collection using the following query:

db.restaurants.findOne()

• To exit, type the following command:

exit

Step 2 - Export data from MongoDB

• To extract data from MongoDB, execute the mongoexport command. This command provides the flexibility to perform detailed exports by specifying the database, collection, field and incorporating a query.

• Let's consider the collection of restaurants from newdb that we previously imported as an example. The export can be executed in the following way:

sudo mongoexport --db newdb -c restaurants --out newdbexport.json

• In certain situations, it might be necessary to export a specific subset of your database collection. Given the structure as well as data within JSON file of restaurants, our objective is to export all restaurants that fulfill the conditions of being located in Bronx borough as well as specializing in Chinese cuisine. For direct retrieval of information from MongoDB while maintaining an active connection, simply reconnect to database.

sudo mongo newdb

• Execute the following query:

db.restaurants.find( { "borough": "Bronx", "cuisine": "Chinese" } )

• To exit, enter the following command:

exit

• If you prefer to export data using sudo command rather than maintaining a database connection, you can incorporate previous query into mongoexport command in the following manner:

sudo mongoexport --db newdb -c restaurants -q "{\"borough\": \"Bronx\", \"cuisine\": \"Chinese\"}" --out Bronx_Chinese_retaurants.json

• Use the commands cat and less to scan through the data:

cat Bronx_Chinese_retaurants.json | less

Conclusion

We have successfully demonstrated how to import and export a MongoDB Database on Ubuntu 20.04.