SQL exersice

One of my mates asked me a question related to building of sql query. She was asked that question on the interview for one IT company and had a difficulties with finding a solution.

Code smells

A couple of days ago I finished reading the wonderful book by Robert Martin "Clean code". Despite all examples were on Java I dived into code in the book with a big pleasure. Robert explains things any developer should know and use every day. Closer to the end of the book he formulates all rules he told about as short and clear "code smells".