SQL Puzzles and Answers (2nd Edition)

SQL Puzzles and Answers (2nd Edition) is a puzzle-collection style work by American database expert Joe Celko. The Chinese edition, translated by Mi Quanxi and published by Posts & Telecom Press in 2008, belongs to the Turing Programming Series · Database Series. The book is built around 75 SQL problems abstracted from real business scenarios, covering topics that range from fiscal-year reports, absence and attendance records, access-control card swipes, hotel room reservations, portfolio tracking, printer job scheduling, payroll and income tax calculations, inventory adjustments, moving averages and depreciation, merging contiguous ranges, string sorting and report formatting, to classic algorithmic puzzles such as Sudoku solving and the stable marriage problem. Each puzzle first presents the table structures and data along with a statement of requirements, then the author offers one or more solutions based on SQL-99 and later standards, comparing different approaches in terms of readability, portability, and execution efficiency; an index at the end of the book makes it easy to look things up by topic. Its focus is not on cataloguing syntax but on training readers to "translate" real-world requirements into set operations and relational operations, which is why readers often use it as a workout book for SQL fundamentals and why it also serves well as a supplementary case collection for university database courses.