This page is a quick reference checkpoint for NTH VALUE in Postgres: behavior, syntax rules, edge cases, and a minimal example; plus the official vendor documentation.
NTH_VALUE returns the value from the nth row in the window frame.
Returns the value of the nth row in the window frame; if the frame is not large enough to include n rows, the result is NULL.
If this behavior feels unintuitive, the tutorial below explains the underlying pattern step-by-step.
NTH_VALUE(value , n) is listed as a window function and requires an OVER clause.
SELECT NTH_VALUE(salary, 2) OVER (ORDER BY salary ROWS BETWEEN UNBOUNDED PRECEDING AND UNBOUNDED FOLLOWING) FROM empsalary;
If you came here to confirm syntax, you’re done. If you came here to get better at window functions, choose your next step.
NTH VALUE is part of a bigger window-function pattern. If you want the “why”, start here: First Last Nth Value
For the authoritative spec, use the vendor docs. This page is the fast “sanity check”.
View Postgres Documentation →Looking for more functions across all SQL dialects? Visit the full SQL Dialects & Window Functions Documentation.