Book Image

Data Analysis Using SQL and Excel - Second Edition

By : Gordon S. S. Linoff
Book Image

Data Analysis Using SQL and Excel - Second Edition

By: Gordon S. S. Linoff

Overview of this book

Data Analysis Using SQL and Excel, 2nd Edition shows you how to leverage the two most popular tools for data query and analysis—SQL and Excel—to perform sophisticated data analysis without the need for complex and expensive data mining tools. Written by a leading expert on business data mining, this book shows you how to extract useful business information from relational databases. You'll learn the fundamental techniques before moving into the "where" and "why" of each analysis, and then learn how to design and perform these analyses using SQL and Excel. Examples include SQL and Excel code, and the appendix shows how non-standard constructs are implemented in other major databases, including Oracle and IBM DB2/UDB. The companion website includes datasets and Excel spreadsheets, and the book provides hints, warnings, and technical asides to help you every step of the way. Data Analysis Using SQL and Excel, 2nd Edition shows you how to perform a wide range of sophisticated analyses using these simple tools, sparing you the significant expense of proprietary data mining tools like SAS.
Table of Contents (18 chapters)
Free Chapter
1
Foreword
17
EULA

Comparing Survival over Time

The subscribers data has three years of complete starts. The analyses so far have mixed all the data together, calculating “average” hazards over the entire period. Have the hazards have changed over time?

This section presents three ways to approach this problem. The first looks at whether a particular hazard has changed over time. The second looks at customers by the year in which they started, answering the question: What is the survival of customers who started in a given year? The third takes snapshots of the hazards at the end of each year, answering the question: What did the hazards look like at the end of each year? All these ways of approaching this question use the same data. They simply require cleverness to calculate the hazards.

The next chapter presents yet another way to look at this problem. It answers the question: What did the hazards look like based on the stops in each year? Answering this question requires a different approach...