This page is a quick reference checkpoint for ROW_NUMBER in SQL Server: behavior, syntax rules, edge cases, and a minimal example; plus the official vendor documentation.
ROW_NUMBER assigns a unique sequential number to each row within the window partition.
Assigns a unique sequential integer to rows within a partition, ordered by the ORDER BY clause; no ties because numbering increments row-by-row.
If this behavior feels unintuitive, the tutorial below explains the underlying pattern step-by-step.
ROW_NUMBER() OVER ( [ PARTITION BY ... ] ORDER BY ... )
SELECT ROW_NUMBER() OVER (ORDER BY SalesYTD DESC) AS RowNum, BusinessEntityID, SalesYTD FROM Sales.SalesPerson ORDER BY SalesYTD DESC;
If you came here to confirm syntax, you’re done. If you came here to get better at window functions, choose your next step.
ROW_NUMBER is part of a bigger window-function pattern. If you want the “why”, start here: Ranking Functions
Reading docs is useful. Writing the query correctly under pressure is the skill.
For the authoritative spec, use the vendor docs. This page is the fast “sanity check”.
View SQL Server Documentation →Looking for more functions across all SQL dialects? Visit the full SQL Dialects & Window Functions Documentation.