What are SQL window functions and how do they work?

What are SQL window functions and how do they work?

SQL window functions perform calculations across a set of table rows related to the current row. They are used for analytics.

Can you give me an example of a window function in SQL?

Sure! A common example is the ROW_NUMBER() function, which assigns a unique number to each row within a partition.

How do I use PARTITION BY with window functions?

You can use PARTITION BY to divide the result set into partitions to which the window function is applied. For example: SELECT name, salary, ROW_NUMBER() OVER (PARTITION BY department ORDER BY salary DESC) FROM employees;

What are some other window functions I should know about?

Other useful window functions include RANK(), DENSE_RANK(), and SUM(), which can all be used with OVER().