دانلود کتاب SQL روایتی – ایجاد پرس‌وجوهای تحلیل داده که داستان می‌گویند

In the past decade, data analysis and SQL have played a central role in my professional career. My passion for query writing began during my bachelor’s studies, where I completed a database course with full marks. As a result of this achievement, I was given the opportunity to become a teaching assistant the following semester, where I gained experience writing queries and explaining them to students. Despite speaking with a trembling voice at first, this role helped me gain confidence in technical communication and public speaking, and enhanced my advanced query-writing skills. These early experiences laid the foundation for my current expertise in SQL and data analysis, fundamental to my next career accomplishment. After a year, I started working for a technology company, where I encountered more complex challenges. As a data analysis intern, two of the challenges I encountered included the lack of neatly organized data and the difficulty of collaborating. It was difficult and very different from teaching or solving textbook exercises to coordinate projects among programmers, query writers, UI/UX designers, and the other members of the team. Despite all the challenges, I was motivated day by day to gain experience and skills from my colleagues and improve my analytical skills to become a data analyst who has an insightful perspective. Throughout the years, I have dealt with a number of projects and gained deeper insights and better analytical skills from the past. One day I decided that I had an insight that I could share with those who are interested in data analysis and query writing. So, I decided to write this book to teach what formed this perspective within me, in as much detail as I could. The core concept of this book is SQL query writing, which is at the core of my day-to-day activities, whether as a data analyst, a university lecturer, or a data team leader. I believe that at the present time, people who are able to shape information into compelling stories hold an advantage in the ever-increasing world of data. Due to this belief, narrative SQL emerged, which is the idea that learning SQL should not be like learning a machine’s language, but should instead feel like mastering a language of communication. This book is for the curious analyst, the thoughtful developer, and the future storyteller of data. This book is designed to provide you with clear and creative guidance regardless of whether you are just beginning your journey into databases or want to improve your proficiency in SQL. Using a narrative structure, this book begins with the basics—simple SELECT statements, filters, and JOINs. In the subsequent chapters, this book explores queries that transform raw data into rich insights, including aggregations, subqueries, conditional logic, and more. With the SQL queries and stories provided, this book is not just a reference guide; it’s a companion for your data journey, helping you think narratively, write clearly, and analyze clearly. Each chapter explores stories that introduce concepts and skills toward mastery of powerful SQL tools, including window functions, subqueries for dynamic data manipulation, conditional logic with complex queries, and even optimization strategies based on indexes and views. Upon completion of this book, you should be able to tackle a wide range of data analysis challenges by writing SQL queries. The last few chapters of this book cover advanced topics such as tuning performance, optimizing scripts, and analytical storytelling with window functions, giving your narratives depth and precision. In this book, you will find both inspiration and practical skills—and when you close the last chapter, you will be prepared to tell your own powerful data stories. Finally, it should be noted that all queries presented in this book have been developed and thoroughly tested on PostgreSQL 14.17, the enterprise-grade open-source relational database system known for its robustness, extensibility, and SQL compliance. Although the fundamental concepts of PostgreSQL should apply to all PostgreSQL versions, specific syntax, performance characteristics, or feature availability might be different. The complete collection of queries, including stories and examples, can be accessed via the publisher’s GitHub repository at https://github.com/Apress/Narrative-SQL. Throughout this repository, all queries are conveniently organized and categorized by chapter, allowing you to find and execute examples relevant to specific sections conveniently.