mysql的循环查询

DELIMITER //

CREATE PROCEDURE UpdateSalaries()
BEGIN
    DECLARE done INT DEFAULT FALSE;
    DECLARE emp_id INT;
    DECLARE current_salary DECIMAL(10, 2);
    DECLARE new_salary DECIMAL(10, 2);

    -- 假设有一个员工表 employees，包含 id 和 salary 字段
    DECLARE cur CURSOR FOR SELECT id, salary FROM employees;
    DECLARE CONTINUE HANDLER FOR NOT FOUND SET done = TRUE;

    OPEN cur;

    read_loop: LOOP
        FETCH cur INTO emp_id, current_salary;
        IF done THEN
            LEAVE read_loop;
        END IF;

        -- 假设我们要给每个员工涨薪10%
        SET new_salary = current_salary * 1.1;

        -- 更新员工薪水
        UPDATE employees SET salary = new_salary WHERE id = emp_id;
    END LOOP;

    CLOSE cur;
END //

DELIMITER ;

-- 调用存储过程
CALL UpdateSalaries();