“That is what learning is. You suddenly understand something you’ve understood all your life, but in a new way.”
—DORIS LESSING
You now have all the tools you need to query or change data in a database successfully. You’ve learned how to create both simple and complex SELECT statements and how to work with various types of data. You’ve also learned how to filter data with search conditions, work with multiple tables using JOINs, and produce statistical information by grouping data. You learned how to update, add, and delete data in your tables. And finally, you learned to “think out of the box” to build solutions to “NOT” and “AND” problems, use condition testing, work with unlinked tables, perform complex grouping, and look at “windows” into your data.
As with any new endeavor, there’s always more to learn. Your next task is to take the techniques you’ve learned in this book and apply them within your database system. Be sure to refer to your database system’s documentation to determine whether there are any differences between standard SQL syntax and the SQL syntax your database uses. If your database allows you to create queries using a graphical interface, you’ll probably find that the interface now makes more sense and is much easier to use.
Also remember that I focused only on the data manipulation portion of SQL—there are still many parts to SQL that you can delve into should you be so inspired. For example, you could learn how to create data structures; incorporate several tables and commands into a single view, function, or stored procedure; or embed SQL statements within an application program. If you want to learn more about SQL, I suggest you start with any of the books I’ve listed in Appendix D, “Suggested Reading.”
I hope you’ve enjoyed reading this book as much as I’ve enjoyed writing it. I know that books on this subject tend to be rather dry, so I decided to have a little fun and inject some humor wherever I could. There’s absolutely no reason why learning should be boring and tedious. On the contrary, you should look forward to learning something new each day.
Writing a book is always a humbling experience. It makes you realize just how much more there is to learn about the subject at hand. And as you work through the writing process, it is inevitable that you’ll see things from a fresh perspective and in a different light. I found out just how much Doris Lessing’s statement rings true.
I hope you will, too.