Chapter 7. Advanced Querying
Over the previous two chapters, you’ve completed an introduction to the basic features of querying and modifying databases with SQL. You should now be able to create, modify, and remove database structures, as well as work with data as you read, insert, delete, and update entries. Over the next three chapters, we’ll look at more advanced concepts. You can skim these chapters and return to read them thoroughly when you’re comfortable with using MySQL.
This chapter teaches you more about querying, giving you skills to answer complex information needs. You’ll learn how to:
Use nicknames, or aliases, in queries to save typing and allow a table to be used more than once in a query
Aggregate data into groups so you can discover sums, averages, and counts
Join tables in different ways
Use nested queries
Save query results in variables so they can be reused in other queries
Understand why MySQL supports several table types
Get Learning MySQL now with the O’Reilly learning platform.
O’Reilly members experience books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers.
