PROGRAD LABS | MONGODB | WORKING WITH QUERY - MODULE 2

Introduction

We learned about databases, and more specifically, about MongoDB. During the rest of the bootcamp, we will keep using MongoDB as our database, so we need to start practicing a bit. As we mentioned before, almost every web app we develop will include CRUD (Create, Read, Update and Delete) operations within the database.

For manipulating our database, we learned how to use Mongo shell and also you can use mongo compass, the official GUI of MongoDB. When developing our website, we will do CRUD operations directly from our code, and later on the bootcamp, we will learn how to integrate everything. But for now, you should focus on learning really well how to do queries, and how to use useful features such as projections, sort, skip or limit.

Deliverables

Since we will be querying our database from Mongo Compass, you will need to copy/paste the query, projection, sort, skip and limit you entered on Mongo Compass. On the PROGRESSION 2, you will find the instructions about the 25 queries you need to do, and a field to fill the answers.

Instructions

Since we will be querying our database from Mongo Shell, you will need to copy/paste the query, projection, sort, skip and limit you entered on Mongo Shell. In the PROGRESSION 2, you will find the instructions about the queries you need to do.

Progression 1

First, we need to import the database we will be using for the lab. We will use the Crunchbase database. Crunchbase is the premier destination for discovering industry trends, investments, and news about hundreds of thousands of companies globally. From startups to Fortune 500s, Crunchbase is recognized as the primary source of company intelligence by millions of users globally.

The database contains more than 18k documents. Each document holds the data about each of the companies. A document looks like the following:

1. You will find the companies.json file of the database on the dataset.zip folder.
2. Unzip the file
3. Navigate to this lab's folder in your terminal, and when inside, import the database to Mongo using the following command:

When running the mongoimport you should be located in the same folder as the data.json file.

$ mongoimport --db companiesDB --collection companies --file companies.json

What this mongoimport will do for us is to create a database named companiesDB, and inside the database will create a collection named companies which will be fed with companies.json.

4. Check on Mongo Compass if everything goes ok:

Progression 2

Let's start doing our queries; we will be doing the first one together:

1. Find all the companies that include 'Facebook' on the name field.

• query: {name: 'Facebook'}

:::info Since we only need a query you just need to copy/paste that field. :::

Let's do it one more together:

2. Find all the companies which category_code is 'web'. Retrive only their name field:

• query: {category_code: 'web'}
• projection: {name: 1, _id: 0}

3. Find all the companies named "Twitter", and retrieve only their name, category_code and founded_year fields.
4. Find all the companies who have web as their category_code, but limit the search to 50 companies.
5. Find all the companies which category_code is 'enterprise' and have been founded in 2005. Retrieve only the name, category_code and founded_year fields.
6. Find all the companies that have been founded on the 2000 or have 20 employees. Sort them descendingly by their number_of_employees.
7. Find all the companies that do not include web nor social on their category_code. Limit the search to 20 documents and retrieve only their name and category_code.
8. Find all the companies that were not founded on 'June'. Skip the first 50 results and retrieve only the founded_month and name fields.
9. Find all the companies that have 50 employees, but do not correspond to the 'web' category_code.
10. Find all the companies that have been founded on the 1st of the month, but does not have either 50 employees nor 'web' as their category_code. Retrieve only the founded_day and name and limit the search to 5 documents.
11. Find all the companies which the price_amount of the acquisition was 40.000.000. Sort them by name.
12. Find all the companies that have been acquired on January of 2014. Retrieve only the acquisition and name fields.

Happy Coding! ❤️