SQL has been powering data-driven applications for over five decades, and in 2026 it remains one of the most in-demand skills across software development, data analytics, and DevOps.
The global database management market is projected to grow from $149 billion to over $400 billion by 2034, driven by cloud adoption, AI pipelines, and the explosion of structured data. Whether you are building payment systems, analytics dashboards, or backend APIs, SQL is the language that ties data to decisions. Understanding how to write efficient queries, design relational schemas, and interact with databases is no longer optional for developers — it is a core competency that defines technical versatility.
About the book
Written by Bobby Iliev, a Linux DevOps engineer with years of hands-on experience, Introduction to SQL is a practical, open-source guide designed for developers, system administrators, and DevOps engineers who want to pick up SQL quickly.
The book focuses on MySQL and walks through everything from database fundamentals to real-world query patterns. No prior SQL knowledge is required — the author starts with what a database is and builds up to joins, subqueries, and command categorization.
The content is concise, example-driven, and structured for self-paced learning. Each chapter includes clear explanations, code snippets, and practical use cases that mirror what you would encounter in production environments.
What you will learn
This book covers the essential SQL skills needed to work with relational databases in modern development and operations contexts. You will learn how to install and configure MySQL, design tables with proper column types, and write queries using SELECT, WHERE, INSERT, UPDATE, and DELETE.
The guide dives into filtering, sorting, grouping, and joining data across tables, then moves into subqueries and SQL command categories (DDL, DML, DCL). By the end, you will be comfortable navigating a MySQL database, writing queries to extract meaningful information, and understanding how databases fit into the broader DevOps and application development lifecycle.
Table of contents
- About the book
- Databases
- MySQL (installation and setup)
- Tables
- Basic Syntax
- SELECT
- WHERE
- ORDER and GROUP BY
- INSERT
- UPDATE
- DELETE
- JOIN
- SQL Command Categories
- Sub Queries
- The MySQL dump command
- Conclusion
Book details
- Title: Introduction to SQL
- Author(s): Bobby Iliev
- Publication year: 2021
- Publisher: Self-published
- Pages: 207
- PDF size: 0.64 MB
- Estimated reading time: ~5 h 10 min
- Level: Beginner
- Main category: Databases
- Subcategory: SQL
- Language: English
- License: MIT License
Legal notice: This book is shared for educational purposes only. The content is distributed under Creative Commons licenses or with explicit permission from the author. FreeProgrammingBooks may host files that comply with their respective licenses.