Modifying MySQL Database Table Constraints

Introduction

In this project, you will learn how to modify the countrylanguage table in a MySQL database by removing the "not null" constraint from the IsOfficial field.

👀 Preview

MariaDB [world]> DESC countrylanguage;
+-------------+---------------+------+-----+---------+-------+
| Field       | Type          | Null | Key | Default | Extra |
+-------------+---------------+------+-----+---------+-------+
| CountryCode | char(3)       | NO   | PRI |         |       |
| Language    | char(30)      | NO   | PRI |         |       |
| IsOfficial  | enum('T','F') | YES  |     | NULL    |       |
| Percentage  | decimal(4,1)  | NO   |     | 0.0     |       |
+-------------+---------------+------+-----+---------+-------+
4 rows in set (0.002 sec)

🎯 Tasks

In this project, you will learn:

• How to start the MySQL database and access it using the sudo command
• How to import the world.sql data file into the MySQL database
• How to modify the countrylanguage table by removing the "not null" constraint from the IsOfficial field
• How to verify the changes made to the countrylanguage table

🏆 Achievements

After completing this project, you will be able to:

• Understand how to work with MySQL databases using the command-line interface
• Modify table structures by altering the constraints on fields
• Verify the changes made to a table by describing its structure