PERCENTILE_CONT

Calculates a percentile, assuming a continuous distribution of values of defined. Results are interpolated, rather than matching any of the specific column values.

PERCENTILE_CONT is available as a window function. See also PERCENTILE_DISC, which returns a percentile equal to a specific column value.

Syntax

PERCENTILE_CONT( <value> ) WITHIN GROUP ( ORDER BY <expression> [ { ASC | DESC } ] )

Parameters

Parameter	Description	Supported input types
`<value>`	Percentile value for the function	`DOUBLE PRECISION`/`REAL` literal between 0.0 and 1.0
`<expression>`	Expression used for the `ORDER BY` clause	`NUMERIC`

Return Types

The return type of the function is DOUBLE. This function ignores NULL values.

Example

The example below calculates the median percentile value based on continuous distribution of student grade levels.

SELECT
	grade_level,
	PERCENTILE_CONT(0.5) WITHIN GROUP (ORDER BY test_score) AS percentile
FROM
	class_test
GROUP BY grade_level;

Returns:

' +-------------+------------+
' | grade_level | percentile | 
' +------------+-------------+
' | 9           |        79.5 |
' | 10          |          78 |
' | 11          |          74 |
' | 12          |          93 |
' +-------------+------------+