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sieve of eratosthenes

SQL

/* Sieve of Eratosthenes in SQL (MySQL)
 * Written by Rob Hoelz
 *
 * To use:
 *  $ mysql
 *  mysql> use <database>
 *  mysql> source sieve.sql
 *  mysql> call sieve(<limit>);
 */

Delimiter //
create procedure sieve (lim int)
  begin
    declare i int;
    create temporary table if not exists primes (num int);
    truncate primes;

    set i = 2;

    while i <= lim do
        insert into primes values (i);
        set i = i + 1;
    end while;

    set i = 2;

    while (i * i) <= lim do
        delete from primes where (num <> i) and (num % i = 0);
        set i = (select num from primes where num > i limit 1);
    end while;

    select num from primes order by num asc;
  end;
//
Delimiter ;

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