The T-SQL PERCENTILE_CONT function is an analytic function and is used in SQL Server database to calculate a percentile based on a continuous distribution of the column value.

PERCENTILE_CONT Syntax

PERCENTILE_CONT ( numeric_literal )
WITHIN GROUP ( ORDER BY order_by_expression [ ASC | DESC ] )
OVER ( [ ] )

PERCENTILE_CONT Example

select b.*,
PERCENTILE_CONT(0.5) WITHIN GROUP (ORDER BY b.id)
OVER (PARTITION BY b.price) AS PercentCount
from books b
order by PercentCount;