Introduction

If you would like to learn how to retrieve information from a database, but don’t know what to begin with, then this book is intended for you. If you are familiar with SQL, or even are a database specialist, it still may be of interest for you to test your level of knowledge.

The goal of this book is to let you learn SQL quickly. Here, «quickly» does not mean «superficially». On the contrary, while leaving aside many aspects of the language, the author tries to convey a thorough understanding of logical data structure, and consequently of constructing correct to give the idea of correct form of query taking into account structure. On top of that, we strongly believe, that reading of this book will contribute to understanding of the problems, which are outside the scope of this work.