Select (SQL) - Window Function

Window Function

A window function in SQL:2003 is an aggregate function applied to a partition of the result set.

For example,

sum(population) OVER( PARTITION BY city )

calculates the sum of the populations of all rows having the same city value as the current row.

Partitions are specified using the OVER clause which modifies the aggregate. Syntax:

:: = OVER ( )

The OVER clause can partition and order the result set. Ordering is used for order-relative functions such as row_number.

Read more about this topic:  Select (SQL)

Famous quotes containing the words window and/or function:

    ‘Who is it that this dark night
    Underneath my window plaineth?’
    Sir Philip Sidney (1554–1586)

    Every boy was supposed to come into the world equipped with a father whose prime function was to be our father and show us how to be men. He can escape us, but we can never escape him. Present or absent, dead or alive, real or imagined, our father is the main man in our masculinity.
    Frank Pittman (20th century)