Calculate Factorial

[mikeadn]

How can you populate a table with factorial values for a population size of 1 - 200?

Mike Cormier
May God bless everything you do...

 

[r937]

could you explain with a bit more detail?

say, for example, give the first few rows ot the table that you'd like to get

rudy | r937.com | Ask the Expert | Premium SQL Articles
SQL for Database-Driven Web Sites (next course starts May 8 2005)

 

[JohnDTampaBay]

Factorials are multiplication of all integers less than or equal to the principal, right?

1! = 1
2! = 2
3! = 6
4! = 24
5! = 120
6! = 720

The cleanest way I can think of is to create a user-defined function that you can use in SELECTs and such:

CREATE FUNCTION dbo.fnFactorial( @principal int )
RETURNS int
AS
BEGIN
  DECLARE @factorial int, @cntr int
  SELECT @cntr = 1, @factorial = 1
  
  WHILE @cntr <= @principal
     SELECT @factorial = @factorial * @cntr,
            @cntr = @cntr + 1
  
  RETURN @factorial
END
-----------------------------
SELECT dbo.fnFactorial(6)

--John
-----------------------------------
Behold! As a wild ass in the desert
go forth I to do my work.
--Gurnie Hallock (Dune)

 

[r937]

returns int" won't do, john

200! is an extremely large number

788657867364790503552363213932185062295135977687173263294742533244359449963403342920304284011984623904177212138919638830257642790242637105061926624952829931113462857270763317237396988943922445621451664240254033291864131227428294853277524242407573903240321257405579568660226031904170324062351700858796178922222789623703897374720000000000000000000000000000000000000000000000000

source:

http://membres.lycos.fr/rsirdey/facttabl.htm

sorry for blowing up the layout of this forum page

rudy | r937.com | Ask the Expert | Premium SQL Articles
SQL for Database-Driven Web Sites (next course starts May 8 2005)

 

[vongrunt]

Exactly how many digits:

create function howmanyfactdigits(@n int)
returns int
as
begin
	declare @digits float; set @digits = 0

	while @n > 1
	begin
		set @digits = @digits + log10(@n)
		set @n = @n-1
	end

	return 1 + convert(int, @digits)
end

------
heisenbug: A bug that disappears or alters its behavior when one attempts to probe or isolate it
schroedinbug: A bug that doesn't appear until someone reads source code and realizes it never should have worked, at which point the program promptly stops working for everybody until fixed.

 

[JohnDTampaBay]

Thanks rudy. Float is being hateful too. I was more concerned with the factorial function than populating the table (bad boy, no spanking). I don't think there is any data numeric data type that will hold this number.

Mike, can you decrease the range of values you want?

--John
-----------------------------------
Behold! As a wild ass in the desert
go forth I to do my work.
--Gurnie Hallock (Dune)