For interview question, the keyword I like best would be EXISTS. Sadly, many developers write SQL for years without knowing its existence. If I am not mistaken, the propel ORM of symfony doesn't even have native support for it.
As shown by codegeek, the 6 questions here can be answered without needing sub-query. Maybe we can add something like "List employees who are not working alone in their department"
As shown by codegeek, the 6 questions here can be answered without needing sub-query. Maybe we can add something like "List employees who are not working alone in their department"