SQL Introduction

Structured Query Language (SQL) is the standard language used to communicate with relational databases. It allows users to store, retrieve, update, and manage data efficiently

What Is SQL For?

SQL allows you to:

• Query data from one or more tables
• Insert, update, or delete records
• Join tables based on relationships
• Sort, filter, and group data
• Handle NULL values, subqueries, and logical conditions

It’s used in web applications, reporting systems, data analysis, backend development, and just about every industry that relies on data including tech, finance, healthcare, retail, education, and logistics.

Why Learn SQL?

• It’s used everywhere, from tech companies to banks to hospitals.
• It works with most relational databases: MySQL, PostgreSQL, SQL Server, Oracle, and even SQLite (used in our playground).
• It gives you control and visibility into your data.

Basic SQL Commands

SQL operates through simple yet powerful commands:

• SELECT – Retrieves data.
• INSERT INTO – Adds new records.
• UPDATE – Modifies existing records.
• DELETE – Removes records.
• CREATE TABLE – Defines new tables.
• DROP TABLE – Deletes tables.

SQL Select Syntax

SELECT * FROM <table>;

SELECT * FROM <table>;