Book Image

SQL for Data Analytics - Third Edition

By : Jun Shan, Matt Goldwasser, Upom Malik, Benjamin Johnston
Book Image

SQL for Data Analytics - Third Edition

By: Jun Shan, Matt Goldwasser, Upom Malik, Benjamin Johnston

Overview of this book

Every day, businesses operate around the clock, and a huge amount of data is generated at a rapid pace. This book helps you analyze this data and identify key patterns and behaviors that can help you and your business understand your customers at a deep, fundamental level. SQL for Data Analytics, Third Edition is a great way to get started with data analysis, showing how to effectively sort and process information from raw data, even without any prior experience. You will begin by learning how to form hypotheses and generate descriptive statistics that can provide key insights into your existing data. As you progress, you will learn how to write SQL queries to aggregate, calculate, and combine SQL data from sources outside of your current dataset. You will also discover how to work with advanced data types, like JSON. By exploring advanced techniques, such as geospatial analysis and text analysis, you will be able to understand your business at a deeper level. Finally, the book lets you in on the secret to getting information faster and more effectively by using advanced techniques like profiling and automation. By the end of this book, you will be proficient in the efficient application of SQL techniques in everyday business scenarios and looking at data with the critical eye of analytics professional.
Table of Contents (11 chapters)
9. Using SQL to Uncover the Truth: A Case Study

Functions and Triggers

So far in this chapter, you have discovered how to quantify query performance via the Query Planner. In this section, you will construct reusable queries and statements via functions, as well as automatic function execution via trigger callbacks. The combination of these two SQL features can be used to not only run queries or re-index tables as data is added to, updated in, or removed from the database but also run hypothesis tests and track their results throughout the life of the database.

Function Definitions

As in almost all other programming or scripting languages, functions in SQL are contained sections of code that provide a lot of benefits, such as efficient code reuse and simplified troubleshooting processes. You can use functions to repeat or modify statements or queries without re-entering the statement each time or searching for its use throughout longer code segments. One of the most powerful aspects of functions is that they allow you to break...