This advanced SQL exercise is part of the book: Advanced SQL – Practical Techniques and Use-Cases, which includes 100 day-to-day SQL challenges (and solutions), need-to-know advanced features, and key concepts.
An interesting SQL puzzle. Given a certain number, for example:
![Advanced SQL - Summarizing Digits [1]](https://i0.wp.com/ramkedem.com/wp-content/uploads/2016/10/word-image-25.png?resize=261%2C182&ssl=1)