create database cunchu;
create table stu(id int,name varchar(50) not null,class varchar(50) not null);
insert into stu values("1","Lucy","class1"),("2","Tom","class1"),("3","Rose","class2");
desc stu;
select * from stu;
mysql> delimiter $
mysql> CREATE PROCEDURE addcount(out count INT)
-> BEGIN
-> DECLARE itmp INT;
-> DECLARE cur_id CURSOR FOR SELECT id FROM stu;
-> DECLARE EXIT HANDLER FOR NOT FOUND CLOSE cur_id;
-> SELECT count(*) INTO count FROM stu;
-> SET @sum= 0;
-> OPEN cur_id;
-> REPEAT
-> FETCH cur_id INTO itmp;
-> IF itmp<10
-> THEN SET @sum=@sum+itmp;
-> END IF;
-> UNTIL 0 END REPEAT;
-> CLOSE cur_id;
-> END;$
CALL addcount(@count)$
SELECT @count,@sum$