FACTORIAL

Description

Returns the factorial of x, or NULL if x is not in the range 0 to 20 (including 0 and 20).

Syntax

FACTORIAL(<x>)

Parameters

Parameter	Description
<x>	The value for which the factorial is to be calculated

Return Value

The factorial value of parameter x.

Special Cases

• When x equals 0, returns 1
• When x is not in the range [0, 20], returns NULL
• When x is NULL, returns NULL

Examples

select factorial(0);

+--------------+
| factorial(0) |
+--------------+
|            1 |
+--------------+

select factorial(-1);

+---------------+
| factorial(-1) |
+---------------+
|          NULL |
+---------------+

select factorial(21);

+---------------+
| factorial(21) |
+---------------+
|          NULL |
+---------------+

select factorial(20);

+---------------------+
| factorial(20)       |
+---------------------+
| 2432902008176640000 |
+---------------------+

select factorial(NULL);

+-----------------+
| factorial(NULL) |
+-----------------+
|            NULL |
+-----------------+