Common mistakes in solving SELECT statement exercises
Then followed a number of exemplary dialogues between the teacher and the student, altogether incomprehensible for the rational ear and absurd in terms of any dualistic or binary logics; teachers mostly answered their students’ questions by beating them on the head with a stick, pouring out a jug of cold water over their head, toeing them out of the room or at best repeating the same question staring into their face.
Hopscotch, Julio Cortazar
In this part of the book, we analyze erroneous solutions to exercises of the learning and first rating stages of the SQL Exercises website. Usually, we don’t provide “correct” solutions – except for the simplest exercises, where we do so to facilitate the initial phase of learning for beginners. Nevertheless, many of the solutions presented here are almost correct, so that fixing them won’t pose any difficulties once the cause of the problem is understood. Some clues are provided in a separate chapter named «Tips and solutions», which contains additional comments and consideration of some alternative solution approaches.