Название: SQL for Data Analysis: Advanced Techniques for Transforming Data into Insights (Fifth Early Release)
Автор: Cathy Tanimura
Издательство: O’Reilly Media, Inc.
Год: 2021-08-17
Страниц: 342
Язык: английский
Формат: epub
Размер: 14.0 MB

With the explosion of data, computing power, and cloud data warehouses, SQL has become an even more indispensable tool for the savvy analyst or data scientist. This practical book reveals new and hidden ways to improve your SQL skills, solve problems, and make the most of SQL as part of your workflow.

You'll learn how to use both common and exotic SQL functions such as joins, window functions, subqueries, and regular expressions in new, innovative ways--as well as how to combine SQL techniques to accomplish your goals faster, with understandable code. If you work with SQL databases, this is a must-have reference.

SQL is the language used to communicate with databases. The acronym stands for “Structured Query Language” and is pronounced either like “sequel” or by saying each letter, as in “ess cue el.” This is only the first of many controversies and inconsistencies surrounding SQL that we’ll see, but most people will know what you mean regardless of how you say it. There is some debate as to whether SQL is or isn’t a programming language. It isn’t a general purpose language in the way that C or Python are. SQL without a database and data in tables is just a text file. SQL can’t build a website, but it is powerful for working with data in databases. On a practical level, what matters most is that SQL can help you get the job of data analysis done.

Learn the key steps for preparing your data for analysis
Perform time series analysis using SQL's date and time manipulations
Use cohort analysis to investigate how groups change over time
Use SQL's powerful functions and operators for text analysis
Detect outliers in your data and replace them with alternate values
Establish causality using experiment analysis, also known as A/B testing