Here is a pseudo random number generator function that is simple to use and has the added capability of limiting the range of random numbers produced. There are times when you don't want just any random number from 1 thru 9999; for example, you may want all the random number to be four digit numbers. This function will produce random numbers of a specific length of digits. The basis of this function is the utilization of the DBMS_UTILITY package. More specifically the GET_HASH_VALUE and GET_TIME functions within this package. It requires two values: a string value to be used as the seed value and the number of digits the random number returned contains. It has been tested on Oracle 8.1.7.
CREATE OR REPLACE function Getrandomnumber (iseed IN VARCHAR2, isize IN INTEGER) return INTEGER IS irandomnbr INTEGER; begin SELECT dbms_utility.get_hash_value(to_char(dbms_utility.get_time)||iseed,to_number( '1'||substr('0000000000',1,isize-1)),to_number('9'||substr('0000000000',1,is ize-1))) INTO irandomnbr FROM dual; return irandomnbr; end Getrandomnumber; /
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This was first published in October 2002