Book Image

SQL for Data Analytics

By : Upom Malik, Matt Goldwasser, Benjamin Johnston
3 (1)
Book Image

SQL for Data Analytics

3 (1)
By: Upom Malik, Matt Goldwasser, Benjamin Johnston

Overview of this book

Understanding and finding patterns in data has become one of the most important ways to improve business decisions. If you know the basics of SQL, but don't know how to use it to gain the most effective business insights from data, this book is for you. SQL for Data Analytics helps you build the skills to move beyond basic SQL and instead learn to spot patterns and explain the logic hidden in data. You'll discover how to explore and understand data by identifying trends and unlocking deeper insights. You'll also gain experience working with different types of data in SQL, including time-series, geospatial, and text data. Finally, you'll learn how to increase your productivity with the help of profiling and automation. By the end of this book, you'll be able to use SQL in everyday business scenarios efficiently and look at data with the critical eye of an analytics professional. Please note: if you are having difficulty loading the sample datasets, there are new instructions uploaded to the GitHub repository. The link to the GitHub repository can be found in the book's preface.
Table of Contents (11 chapters)
9. Using SQL to Uncover the Truth – a Case Study

Basic Data Types of SQL

As previously mentioned, each column in a table has a data type. We review the major data types here.


Numeric data types are data types that represent numbers. The following diagram provides an overview of some of the major types:

Figure 2.1: Major numeric data types


Character data types store text information. The following diagram summarizes the character data types:

Figure 2.2: Major character data types

Under the hood, all of the character data types use the same underlying data structure in PostgreSQL and many other SQL databases, and most modern developers do not use char(n).


Booleans are a data type used to represent True or False. The following table summarizes values that are represented as a Boolean when used in a query with a Boolean data column type:

Figure 2.3: Accepted Boolean values

While all of these values are accepted, the...