This week's book giveaways are in the Refactoring and Agile forums. We're giving away four copies each of Re-engineering Legacy Software and Docker in Action and have the authors on-line! See this thread and this one for details.
How to identify which is a subquery and which is correlate subquery?i understand the difference between correlated subquery and subquery
(got information like subqeury executed only one and correlated subquery executes several times)
i read the rollup function, but i can't understand the functionality.
if anybody knows, please explain with simple example(rollup by more than 2 columns)