SQL Server provides us with a number of window functions that help us to perform calculations across a set of rows, without the need to repeat the calls to the database. Unlike the standard aggregate functions, the window functions will not group the rows into a single output row, they will return a single aggregated value for each row, keeping the separate identities for those rows. The Window term here is not related to the Microsoft Windows operating system, it describes the set of rows that the function will process. One of the most useful types of window functions is Ranking Window Functions that are used to rank specific field values and categorize them according to the rank of each row, resulting in a single aggregated value for each participated row. There are four ranking window functions supported in SQL Server; ROW_NUMBER(), RANK() , DENSE_RANK() and NTILE() . All these functions are used to calculate ROWID for the provided rows window in ...