CREATE PROCEDURE IncreaseSalary()
BEGIN
    DECLARE emp_count INT;
    DECLARE i INT DEFAULT 0;
    DECLARE emp_id INT;
    DECLARE emp_salary DECIMAL(10, 2);
    -- 获取员工数量
    SELECT COUNT(*) INTO emp_count FROM employees;
    -- 循环遍历并更新薪水
    WHILE i < emp_count DO
        SET i = i + 1;
        -- 获取当前员工的id和薪水
        SELECT id, salary INTO emp_id, emp_salary FROM employees WHERE id = i;
        -- 对薪水进行增加
        UPDATE employees SET salary = emp_salary * 1.1 WHERE id = emp_id;
    END WHILE;
END;

DELIMITER $$
CREATE PROCEDURE DisplayEmployeesWithRepeatUntil()
BEGIN
--声明变量
    DECLARE emp_count INT;--员工数量
    DECLARE i INT DEFAULT 1;
    DECLARE emp_id INT;
    DECLARE emp_name VARCHAR(50);
    DECLARE emp_age INT;
    DECLARE emp_salary DECIMAL(10, 2);
    -- 获取员工数量
    SELECT COUNT(*) INTO emp_count FROM employees;
    -- 循环遍历并输出员工信息
    REPEAT
        -- 获取当前员工信息
        SELECT id, name, age, salary INTO emp_id, emp_name, emp_age, emp_salary FROM employees WHERE id = i;
        -- 输出员工信息
        SELECT CONCAT('ID: ', emp_id, ', Name: ', emp_name, ', Age: ', emp_age, ', Salary: ', emp_salary) AS employee_info;
        SET i = i + 1;
    UNTIL i > emp_count END REPEAT;
END$$
DELIMITER ;

CREATE PROCEDURE DisplayEmployeesWithLoop()
BEGIN
    DECLARE emp_count INT;
    DECLARE i INT DEFAULT 1;
    DECLARE emp_id INT;
    DECLARE emp_name VARCHAR(50);
    DECLARE emp_age INT;
    DECLARE emp_salary DECIMAL(10, 2);
    -- 获取员工数量
    SELECT COUNT(*) INTO emp_count FROM employees;
    -- 循环遍历并输出员工信息
    emp_loop: LOOP
        -- 获取当前员工信息
        SELECT id, name, age, salary INTO emp_id, emp_name, emp_age, emp_salary FROM employees WHERE id = i;
        -- 输出员工信息
        SELECT CONCAT('ID: ', emp_id, ', Name: ', emp_name, ', Age: ', emp_age, ', Salary: ', emp_salary) AS employee_info;
        SET i = i + 1;
        IF i > emp_count THEN
            LEAVE emp_loop;
        END IF;
    END LOOP;
END;