Re: random numbers
Date: Sun, 02 Aug 1998 22:23:02 +0100
Message-ID: <35C4D8B5.297D49E0_at_janjua.demon.co.uk>
Hi Dennis
I found this package on internet. Its works fine and generates Random Numbers.
I hope it will solve your problem.
Bye
AAJ The package..
package random is
/* Linear congruential random number generator */
/* Returns random integer between [0, r-1] */ function rndint(r in number) return number;
/* Returns random real between [0, 1] */ function rndflt return number;
end; /* package random */
package body random is
/* Linear congruential random number generator */
m constant number:=100000000; /* initial conditions */ m1 constant number:=10000; /* (for best results) */ b constant number:=31415821; /* */ a number; /* seed */ the_date date; /* */ days number; /* for generating initial seed */ secs number; /* */ /*-------------------------- mult ---------------------------*//* Private utility function */
function mult(p in number, q in number) return number is
p1 number; p0 number; q1 number; q0 number;
begin
p1:=trunc(p/m1); p0:=mod(p,m1); q1:=trunc(q/m1); q0:=mod(q,m1);
return(mod((mod(p0*q1+p1*q0,m1)*m1+p0*q0),m)); end; /* mult */
/*-------------------------- rndint --------------------------*//* Returns random integer between [0, r-1] */
function rndint (r in number) return number is begin
/* generate a random number and set it to be the new seed */ a:=mod(mult(a,b)+1,m);
/* convert it to integer between [0, r-1] and return it */
return(trunc((trunc(a/m1)*r)/m1));
end; /* rndint */
/*-------------------------- rndflt --------------------------*//* Returns random real between [0, 1] */
function rndflt return number is
begin
/* generate a random number and set it to be the new seed */ a:=mod(mult(a,b)+1,m);
/* return it */
return(a/m);
end; /* rndflt */
begin /* package body random */
/* Generate an initial seed "a" based on system date */
/* (Must be connected to database.) */the_date:=sysdate;
days:=to_number(to_char(the_date, 'J')); secs:=to_number(to_char(the_date, 'SSSSS')); a:=days*24*3600+secs;
end; /* package body random */
Dennis M. Hancy wrote:
> Is there a function in SQL to produce random numbers?
>
> Dennis Hancy
> Eaton Corporation
> Cleveland, OH
Received on Sun Aug 02 1998 - 23:23:02 CEST