[Note from Pinal]: This is a 97th episode of Notes from the Field series. If you know Mike Walsh, he is an amazing person to meet and know. I am fortunate to be his friend. Every single time I meet him, I learn something as a human. In this episode of the Notes from the Field series database expert Mike Walsh gives a challenge to all of us. He explains to us why we should study our mistakes. He is indeed very right that every mistake gives us opportunity to correct ourselves.
You can assign a new name for a derived column in the SELECT statement which is also known as an alias name. But you need to understand how column alias are assigned and its scope