Head First SQL, Second Edition (Third Early Release) (Kimberley Fessel) (Z-Library)

Head First SQL SECOND EDITION A Learner’s Guide to Querying and Managing Data With Early Release ebooks, you get books in their earliest form—the author’s raw and unedited content as they write —so you can take advantage of these technologies long before the official release of these titles. Kimberly Fessel

Head First SQL by Kimberly Fessel Copyright © 2026 Dr Kim Data LLC. All rights reserved. Printed in the United States of America. Published by O’Reilly Media, Inc. , 1005 Gravenstein Highway North, Sebastopol, CA 95472. O’Reilly books may be purchased for educational, business, or sales promotional use. Online editions are also available for most titles ( http://oreilly.com ). For more information, contact our corporate/institutional sales department: 800-998-9938 or corporate@oreilly.com . Editors: Melissa Potter and David Michelson Production Editor: Katherine Tozer Interior Designer: David Futato Cover Designer: Karen Montgomery Illustrator: Kate Dullea August 2026: Second Edition

Revision History for the Early Release 2024-02-13: First Release 2024-03-29: Second Release 2024-05-07: Third Release See http://oreilly.com/catalog/errata.csp?isbn=9781098163655 for release details. The O’Reilly logo is a registered trademark of O’Reilly Media, Inc. Head First SQL, the cover image, and related trade dress are trademarks of O’Reilly Media, Inc. The views expressed in this work are those of the author and do not represent the publisher’s views. While the publisher and the author have used good faith efforts to ensure that the information and instructions contained in this work are accurate, the publisher and the author disclaim all responsibility for errors or omissions, including without limitation responsibility for damages resulting from the use of or reliance on this work. Use of the information and instructions contained in this work is at your own risk. If any code samples or other technology this work contains or describes is subject to open source licenses or the intellectual

property rights of others, it is your responsibility to ensure that your use thereof complies with such licenses and/or rights. 978-1-098-16359-4 []

Brief Table of Contents (Not Yet Final) Chapter 1: Data and Tables (available) Chapter 2: Inserting Data (available) Chapter 3: The SELECT Statement (available) Chapter 4: CRUD Operations (available) Chapter 5: Advanced SELECT (unavailable) Chapter 6: Smart Table Design: Normalization and Multiple Tables (unavailable) Chapter 7: Efficiency Considerations: Data Types and Indexes (unavailable) Chapter 8: Join Types (unavailable) Chapter 9: Subqueries (unavailable) Chapter 10: Temporary Tables and Table Variables (unavailable) Chapter 11: Stored Procedures and Functions (unavailable) Chapter 12: Constraints and Views (unavailable)

Chapter 13: Locking, Blocking, and Isolation (unavailable) Chapter 14: Security (unavailable) Chapter 15: Databases and the Cloud (unavailable) Chapter 16: SQL Across Other Databases (unavailable) Appendix: Installing MySQL on Mac or Windows (unavailable)

Chapter 1. Databases and Tables: Organizing Your Information A NOTE FOR EARLY RELEASE READERS With Early Release ebooks, you get books in their earliest form —the author’s raw and unedited content as they write—so you can take advantage of these technologies long before the official release of these titles. This will be the 1st chapter of the final book. Please note that the GitHub repo will be made active later on. If you have comments about how we might improve the content and/or examples in this book, or if you notice missing material within this chapter, please reach out to the editor at mpotter@oreilly.com.

Figure 1-1.   It’s time to bring order to your data. These days, just about every aspect of life involves data: the applications on your phone, the appearance of your social media feed, and even those detailed notes you take about your flossing habits. But all that information can only be useful if it’s arranged in a meaningful way so you can find what you want, when you want it. You need a system to help you store and organize your data, and you need it now. Tables allow you to establish law and order and to craft your bits of info into rich assets, ready to be

mined for insights. So turn the page, come on in, and get ready to enjoy the orderly world of relational databases. Defining your data

Figure 1-2.   Abby’s created quite a large assortment of notebooks, scraps of paper, and other records. Her collection is starting to get overwhelming. It’s so large that she can’t find all the details for her travels anymore, which is a bummer since she wants to

take a big trip this year. Let’s give her a hand so she can get back to her adventures! Figure 1-3.  

BRAIN POWER Figure 1-4.   Is there a better way to organize this information? Do you have any notes like these that could use a better organization system?

Figure 1-5.   Exactly. A database is just what we need.

A database brings order to chaotic data. It’s a digital representation of all your notes and records. When you create a database, you can structure your information in a neat and logical format. And once your data is organized, you can easily access the contents of your database any time you need! But before you create a database for Abby’s travel information, you’re going to need to have a better idea of what kinds of data you want to store and some ways of categorizing it.

SHARPEN YOUR PENCIL Figure 1-6.   Here are a few of Abby’s notes. What types of information do these entries have in common? Give each category of information a descriptive label and write those labels in the space provided below. We’ve added a few to get you started.

Figure 1-7.  

SHARPEN YOUR PENCIL SOLUTION Figure 1-8.   Here are a few of Abby’s notes. What types of information do these entries have in common? Give each category of information a descriptive label and write those labels in the space provided below. We’ve added a few to get you started.

Figure 1-9.   Think about your data in categories

Let’s look at Abby’s travel data in a new way. Imagine cutting up one of her notebook pages, and then spreading the pieces out horizontally like this: Figure 1-10.   Now take the labels that you just made for each category, and place those above the corresponding bits information like this: Figure 1-11.   Build a table of information You can follow this same process for each of Abby’s travel notes, and eventually, you’ll end up with a table of information with columns and rows. Here’s a few of those records in a nice table: