Largest Population by Country

Introduction

In this project, you will learn how to access a MySQL database, import data, and query the top 10 countries by total population from the city table.

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🎯 Tasks

In this project, you will learn:

• How to access MySQL using the sudo command without a password
• How to import data from a SQL script into a MySQL database
• How to write a SQL query to retrieve the top 10 countries by total population from the city table

🏆 Achievements

After completing this project, you will be able to:

• Efficiently access and manage a MySQL database
• Understand how to import and work with data in a MySQL database
• Write SQL queries to retrieve and analyze data from a database

Skills Graph

Access MySQL and Import Data

In this step, you will learn how to access MySQL using the sudo command without any password and import the data from the world.sql script.

1. Open a terminal and start the MySQL service using the following command:

sudo service mysql start

2. Access MySQL using the sudo command without any password:

sudo mysql

3. Import the data from the world.sql script into the MySQL database:

SOURCE /home/labex/project/world.sql;

This will import the data from the world.sql script into the MySQL database.

Query the Top 10 Countries by Population

In this step, you will learn how to query the total population of the countries from the city table, sort them by population in descending order, and retrieve the top 10 records.

1. Create a new SQL script file named getBigPopulation.sql in the /home/labex/project/ directory.

2. Open the getBigPopulation.sql file and add the following SQL query:

SELECT CountryCode AS 'Country Code', SUM(Population) AS 'Total Population'
FROM city
GROUP BY CountryCode
ORDER BY SUM(Population) DESC
LIMIT 10;

This query will:

• Select the CountryCode and the sum of Population (as Total Population) from the city table.
• Group the results by CountryCode.
• Order the results by the Total Population in descending order.
• Limit the results to the top 10 records.

3. Save the getBigPopulation.sql file.

Run the Query Script

In this step, you will learn how to run the getBigPopulation.sql script in MySQL.

1. In the MySQL prompt, run the following command to execute the getBigPopulation.sql script:

SOURCE /home/labex/project/getBigPopulation.sql;

This will execute the SQL query in the getBigPopulation.sql script and display the results.

The output should look similar to the following:

MariaDB [world]> SOURCE /home/labex/project/getBigPopulation.sql;
+--------------+------------------+
| Country Code | Total Population |
+--------------+------------------+
| CHN          |        175953614 |
| IND          |        123298526 |
| BRA          |         85876862 |
| USA          |         78625774 |
| JPN          |         77965107 |
| RUS          |         69150700 |
| MEX          |         59752521 |
| KOR          |         38999893 |
| IDN          |         37485695 |
| PAK          |         31546745 |
+--------------+------------------+
10 rows in set (0.005 sec)

This completes the project. You have successfully queried the top 10 countries by total population from the city table in the MySQL database.

Summary

Congratulations! You have completed this project. You can practice more labs in LabEx to improve your skills.