# row_number¶

## Description¶

Return the window index of the row within its groupby, when ordered by the orderby. Row indexes start at 1.

int64

## Domain¶

This is a window function (calculates over a group of multiple input rows using windowing.)

## Usage¶

row_number( )


## Examples¶

make_col index:window(row_number(), group_by(category_id), order_by(item_cost))


Assigns an index to items, when ordered by cost, grouped by category. The cheapest item in each category will be given the index 1.

## Aliases¶

rownumber (deprecated)