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

Using Array Data types in PostgreSQL

While the PostgreSQL data types that you have explored so far allow you to store many different types of data, occasionally you will want to store a series of values in a table. For example, you might want to store a list of the products that a customer has purchased or the employee ID numbers associated with a specific dealership. For this scenario, PostgreSQL offers the ARRAY data type, which allows you to store a list of values.

Starting with Arrays

PostgreSQL arrays allow you to store multiple values in a field in a table. For example, consider the following first record in the customers table:

customer_id        | 1
title              | NULL
first_name         | Arlena
last_name          | Riveles
suffix             | NULL
email              | [email protected]
gender             | F
ip_address         |
phone              | NULL
street_address     | NULL
city               | NULL
state              | NULL...