factorial_fl()

Calculate factorial.

The function factorial_fl() is a UDF (user-defined function) that calculates factorial of positive integers (n!). It's a simple wrapper of the native gamma() function.

Syntax

factorial_fl(n)

Learn more about syntax conventions.

Parameters

Name	Type	Required	Description
n	int	✔️	The input integer for which to calculate the factorial.

Function definition

You can define the function by either embedding its code as a query-defined function, or creating it as a stored function in your database, as follows:

Query-defined

Define the function using the following let statement. No permissions are required.

Important

A let statement can't run on its own. It must be followed by a tabular expression statement. To run a working example of factorial_fl(), see Example.

let factorial_fl=(n:int)
{
    gamma(n+1)
};
// Write your query to use the function here.

Stored

Define the stored function once using the following .create function. Database User permissions are required.

Important

You must run this code to create the function before you can use the function as shown in the Example.

.create-or-alter function with (folder = "Packages\\Stats", docstring = "Calculate factorial")
factorial_fl(n:int)
{
    gamma(n+1)
}

Example

Query-defined

Run the query

let factorial_fl=(n:int)
{
    gamma(n+1)
};
range x from 1 to 10 step 3
| extend fx = factorial_fl(x)

Stored

Important

For this example to run successfully, you must first run the Function definition code to store the function.

Run the query

range x from 1 to 10 step 3
| extend fx = factorial_fl(x)

Output

x	fx
1	1
4	24
7	5040
10	3628799