MySQL Sieve of Eratosthenes prime number generator

mysql_prime_number_generator.sql

DELIMITER $$

DROP PROCEDURE IF EXISTS prime $$

CREATE PROCEDURE prime (n INT, OUT res varchar(8000)) 
BEGIN
	DECLARE i smallint DEFAULT 2;
	DECLARE j smallint;
	DECLARE isPrime bit;
	DECLARE result varchar(8000) DEFAULT '';

	WHILE i < n 
    DO		
		SET isPrime = 1;
		SET j = 2;
        
		primalityTestLoop: REPEAT 
			IF i != j and i % j = 0 
			THEN
				SET isPrime = 0;
				LEAVE primalityTestLoop;
			END IF; 				
            
			SET j = j + 1; 
		UNTIL j * j > i
		END REPEAT primalityTestLoop;

		IF isPrime = 1 
        THEN
			SET result = concat(result, CAST(i AS char(4)),  '&');
		END IF;
        
		SET i = i + 1;
        
	END WHILE;
    
	SET res = LEFT(result, length(result) - 1);

END $$

DELIMITER ;

SET @res = '';
CALL prime(1000, @res);
SELECT @res;