The T-SQL PERCENT_RANK function is an analytic function and is used in SQL Server database to calculate the relative rank of a row within a group of rows.

PERCENT_RANK Syntax

PERCENT_RANK( )
OVER ( [ partition_by_clause ] order_by_clause )

PERCENT_RANK Example

select b.*,
PERCENT_RANK() OVER (ORDER BY b.price ) AS PctRank
from books b;