A library provides a more easy way to describe DataFrame schema for Spark and [MLSQL](http://www.mlsql.tech).
 | SQL Pocket Guide: A Guide to SQL Usage (2021) by Zhao, Alice |
 | SQL for Data Analysis: Advanced Techniques for Transforming Data into Insights (2021) by Tanimura, Cathy |
 | Practical SQL, 2nd Edition: A Beginner's Guide to Storytelling with Data (2022) by DeBarros, Anthony |
 | Learning SQL: Generate, Manipulate, and Retrieve Data (2020) by Beaulieu, Alan |
