SQL All-in-One For Dummies, 4th Edition

Introduction

SQL is the internationally recognized standard language for dealing with data in relational databases. Developed by IBM, SQL became an international standard in 1986. The standard was updated in 1989, 1992, 1999, 2003, 2008, 2011, 2016, and 2023. It continues to evolve and gain capability. Database vendors continually update their products to incorporate the new features of the ISO/IEC standard. (For the curious out there, ISO is the International Organization for Standardization, and IEC is the International Electrotechnical Commission.)

SQL isn’t a general-purpose language, such as C++ or Java. Instead, it’s strictly designed to deal with data in relational databases. With SQL, you can carry out all the following tasks:

• Create a database, including all tables and relationships.
• Fill database tables with data.
• Change the data in database tables.
• Delete data from database tables.
• Retrieve specific information from database tables.
• Grant and revoke access to database tables.
• Protect database tables from corruption due to access conflicts or user mistakes.

About This Book

This book isn’t just about SQL; it’s also about how SQL fits into the process of creating and maintaining databases and database applications. In this book, I cover how SQL fits into the larger world of application development and how it handles data coming in from other computers, which may be on the other side of the world or even in interplanetary space.

Here are some of the things you can ...