MySQL笔记（八）存储过程练习&补充

 存储过程有什么优缺点？为什么要用存储过程？或者在什么情况下才用存储过程？

 最直白的好处是存储过程比较快。

1、利用存储过程，给Employee表添加一条业务部门员工的信息。

DROP PROCEDURE IF EXISTS insert_business_employee;
DELIMITER //

CREATE PROCEDURE insert_business_employee(
    IN employee_no_in varchar(8),
    IN employee_name_in varchar(10),
    IN sex_in char(1),
    IN birthday_in date,
    IN address_in varchar(50),
    IN telephone_in varchar(20),
    IN hiredate_in date,
    -- IN department_in varchar(30),
    IN headship_in varchar(10),
    IN salary_in decimal(8,2)
)
BEGIN
    INSERT INTO employee
    (employee_no,
    employee_name,
    sex,
    birthday,
    address,
    telephone,
    hiredate,
    department,
    headship,
    salary)
    VALUES
    (employee_no_in,
    employee_name_in,
    sex_in,
    birthday_in,
    address_in,
    telephone_in,
    hiredate_in,
    '业务部',
    headship_in,
    salary_in);
END // 

DELIMITER ;

CALL insert_business_employee(
    '2222',
    '无极',
    'F',
    '2001-10-22',
    '北海道',
    '1231232',
    '2001-10-22',
    '老板',
    '1333232'
);

2、利用存储过程输出所有客户姓名、客户订购金额及其相应业务员的姓名。

DROP PROCEDURE IF EXISTS print_transaction;
DELIMITER //
CREATE PROCEDURE print_transaction()
BEGIN    
    SELECT 
     customer_name, 
     order_sum, 
     employee_name
    FROM 
     customer x 
     LEFT JOIN order_master y ON x.customer_no = y.customer_no
     LEFT JOIN employee z ON y.saler_no = z.employee_no;
END // 
DELIMITER ;
CALL print_transaction();

3、利用存储过程查找某员工的员工编号、订单编号、销售金额。

DROP PROCEDURE IF EXISTS select_employee_performance;
DELIMITER //
CREATE PROCEDURE select_employee_performance(
    IN employee_name_in varchar(10)
)
BEGIN
    SELECT
     saler_no,
     order_no,
     order_sum
    FROM
     employee
    LEFT JOIN order_master ON employee_no = saler_no
    WHERE
     employee_name = employee_name_in
    ORDER BY 
     saler_no;
END // 
DELIMITER ;
CALL select_employee_performance('张小梅');

4、相关

WEB 开发相关笔记 #05# BUG 日志 持续更新

5、插入一条学生记录，判断学号是否存在。

DROP PROCEDURE IF EXISTS inserStu;
DELIMITER //
CREATE PROCEDURE inserStu(
    IN id_in INT,
    IN name_in VARCHAR(50)
)
BEGIN
    IF EXISTS (SELECT * FROM stu WHERE id = id_in) THEN
     SELECT "学号已存在";
    ELSE
     INSERT INTO stu
     (id,
     name)
     VALUES
     (id_in,
     name_in);
     SELECT "插入成功";    
    END IF;
END // 
DELIMITER ;

-- 测试
-- CALL inserStu(1, 'wang');
-- CALL inserStu(1, 'wang');
-- CALL inserStu(333, 'wang');