What is SQL?

SQL stands for Structured Query Language— a language used to store, manage, and retrieve data in databases.

Why Should You Learn SQL?

Whether you’re a data analyst, developer, or simply work with data, SQL is the essential tool for accessing and organizing information efficiently.

With SQL, you can:

• Retrieve specific data from large datasets
• Insert, update, or delete records
• Create and manage database structures (tables, views, indexes)

A Quick History

SQL was developed in the 1970s by IBM researchers and later standardized by ANSI.

It became the foundation of many popular relational database systems like:

• MySQL
• PostgreSQL
• SQLite
• Oracle Database
• Microsoft SQL Server

What Does SQL Look Like?

Assume you have a table called users with the following columns:

id	name	email	age
1	Alice	alice@example.com	15
2	Bob	bob@example.com	30
3	Charlie	charlie@example.com	25

Here's a simple SQL query that gets data from a table:

Basic SQL SELECT Query

SELECT name, age
FROM users
WHERE age > 20;

This means:

• Get the name and age columns
• From the users table
• Where the user's age is greater than 20

The result will be:

name	age
Bob	30
Charlie	25

Simply put, SQL is a language used to store large amounts of data in a spreadsheet-like format, similar to Excel, and to retrieve that data based on specific conditions.

Real-World Use Cases

SQL is widely used across industries, for example:

• A marketing team checks customer activity from a sales database.
• A web app fetches user data from a backend database.
• A data scientist prepares and filters data before modeling.

Mastering SQL can open up a lot of career opportunities and help you build a strong foundation in the data field.

Coding Practice

Try running this SQL query in the code editor:

Select id, name, and email columns

SELECT id, name, email
FROM students;

This will select the id, name, and email columns from the students table.

You'll see every row and column in the table—like viewing a spreadsheet.