AI engineering glossary · SQL databases
What is ROW_NUMBER?
ROW_NUMBER: A window function that gives each row a unique sequence number 1, 2, 3 within its partition, following the ORDER BY of the window. Ties get different numbers. It is the standard way to pick the top row per group or remove duplicates.
ROW_NUMBER: an example
ROW_NUMBER() OVER (PARTITION BY customer_id ORDER BY order_date DESC) = 1 selects each customer's latest order.
Related terms
More SQL databases terms
Where you learn it
ROW_NUMBER is part of the AI Engineering Program, which teaches it with notes, a hands-on lab and an exam. The first lesson is free.