delimiter $
create procedure pro_testWhile(IN sum INT, OUT result INT)
BEGIN
	-- 定义一个局部变量
	declare i int default 1;
	declare vsum int default 0;
	while i<=sum do
		set vsum=vsum+i;
		set i=i+1;
	end while;
	set result=vsum;
END $

-- ---------------

CALL pro_testWhile(100,@result);
select @result;