游标使用的整个过程：

1.创建游标

DECLARE calc_bonus CURSOR FOR SELECT id, salary, commission FROM employees;

2.打开游标

OPEN calc_bonus;

3.使用游标

FETCH calc_bonus INTO re_id, re_salary, re_comm;

4.关闭游标

CLOSE calc_bonus;

==================================================================================================

以前面提到的计算奖金为实例,给出一个存储过程，在其中使用游标：

DELIMITER //

CREATE PROCEDURE calculate_bonus()

BEGIN

    DECLARE emp_id INT;

    DECLARE sal DECIMAL(8, 2);

    DECLARE comm DECIMAL(3, 2);

    DECLARE done INT;

    DECLARE calc_bonus CURSOR FOR SELECT id, salary, commission FROM employees;

    DECLARE CONTINUE HANDLER FOR NOT FOUND SET done = 1;

    OPEN calc_bonus;

    BEGIN_calc: LOOP

        FETCH calc_bonus INTO emp_id, sal, comm;

        IF done THEN

            LEAVE begin_calc;

        IF sal > 60000 THEN

            IF comm > 0.05 THEM

                UPDATE employees SET bonus = sal * comm WHERE id = emp_id;

            ELSEIF comm <= 0.05 THEN

                UPDATE employees SET bonus = sal * 0.03 WHERE id = emp_id;

            END IF;

        ELSE

            UPDATE employees SET bonus = sal * 0.07 WHERE id = emp_id;

        END IF;

    END LOOP begin_calc;

    CLOSE calc_bonus;

END//

DELIMITER ;

游标使用的整个过程：