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( <val> ) WITHIN GROUP ( ORDER BY <expr> [ { ASC | DESC } ] )


Parameter	Description
`<val>`	A `DOUBLE PRECISION`/`REAL` literal between 0.0 and 1.0.
`<expr>`	A numeric expression used for the order by clause.

The expression used for the order by clause must be of numeric or time data types. The return type of the function will be the same as the expression type. 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 |
' +-------------+------------+