SQL Quick Reference

SQL Quick Reference is a working desk reference, not a course. It assumes you already know what a mean and a standard deviation are, and gets straight to the SQL syntax you need to pull them out of a database, compute them in-query, and reproduce the result six months later.

Unlike this series' Python and R titles, SQL Quick Reference is language-independent by nature -- every mainstream engine (PostgreSQL, MySQL, SQL Server, SQLite, BigQuery) speaks a dialect of the same standard. Ten chapters build from first queries through aggregation, joins, subqueries and CTEs, window functions, hand-rolled descriptive statistics, schema design and constraints, transactions, indexing and query performance, and finally connecting SQL to Python and R for real analysis work. A one-page syntax appendix closes the book for the fastest possible lookup.

Every code listing in this book was run against SQLite and its output shown exactly as produced -- chosen as the primary dialect because it requires no server, no installation, and no configuration, so every listing here is something you can paste and run immediately. Wherever another engine's syntax differs in a way that matters -- PostgreSQL's and SQL Server's window-function edge cases, MySQL's string-concatenation operator, SQLite's own gaps around RIGHT JOIN, ANY/ALL, and stored procedures -- the book calls it out explicitly rather than pretending one dialect is universal. If your own output differs, something in your environment differs too, and that is worth tracking down before moving on.