Mysql中TIMESTAMPDIFF函数的语法与练习案例

-- 相差：25秒
SELECT TIMESTAMPDIFF(SECOND,'2022-04-23 14:57:00','2022-04-23 14:57:25');
-- 相差：5分钟
SELECT TIMESTAMPDIFF(MINUTE,'2022-04-23 15:00:00','2022-04-23 15:05:00');
-- 相差：5小时
SELECT TIMESTAMPDIFF(HOUR,'2022-04-23 11:20:00', '2022-04-23 16:20:00');
-- 相差：2天
SELECT TIMESTAMPDIFF(DAY,'2022-04-23 11:20:00', '2022-04-25 11:20:00');
-- 相差：1星期
SELECT TIMESTAMPDIFF(WEEK,'2022-04-23 11:20:00', '2022-04-30 11:20:00');
-- 相差：1月
SELECT TIMESTAMPDIFF(MONTH,'2022-04-23 11:20:00', '2022-05-30 11:20:00');
-- 相差：1季度
SELECT TIMESTAMPDIFF(QUARTER,'2022-04-23 11:20:00', '2022-07-23 11:20:00');
-- 相差：1年
SELECT TIMESTAMPDIFF(YEAR,'2022-04-23 11:20:00', '2023-04-23 11:20:00');

-- 可以结合日期函数进行搭配使用
SELECT TIMESTAMPDIFF(SECOND,'2022-04-23', CURRENT_DATE());
SELECT TIMESTAMPDIFF(SECOND,'2022-04-23 15:15:00',NOW());
SELECT TIMESTAMPDIFF(SECOND,'2022-04-23 15:15:00',CURRENT_TIMESTAMP());
 
-- 上述日期函数补充说明
-- CURRENT_DATE()用于返回当前时间
-- 示例结果:2022-04-27
SELECT CURRENT_DATE();
 
-- NOW()用于返回当前日期和时间
-- 示例结果:2022-04-27 11:27:28
SELECT NOW();
 
-- CURRENT_TIMESTAMP()用于返回当前日期和时间
-- 示例结果:2022-04-27 11:30:25
SELECT CURRENT_TIMESTAMP();

DROP TABLE IF EXISTS Student;
CREATE TABLE Student (
	SId VARCHAR (10),
	Sname VARCHAR (10),
	Sage datetime,
	Ssex VARCHAR (10)
)
ENGINE = InnoDB 
DEFAULT CHARSET = utf8;
INSERT INTO Student(SId,Sname,Sage,Ssex)
VALUES('01' , '赵雷' , '1990-01-01' , '男')
,('02' , '钱电' , '1990-12-21' , '男')
,('03' , '孙风' , '1990-05-20' , '男')
,('04' , '李云' , '1990-08-06' , '男')
,('05' , '周梅' , '1991-12-01' , '女')
,('06' , '吴兰' , '1992-03-01' , '女')
,('07' , '郑竹' , '1989-07-01' , '女')
,('08' , '张三' , '2017-12-20' , '女')
,('09' , '李四' , '2017-12-25' , '女')
,('11' , '李四' , '2017-12-30' , '女')
,('12' , '孙七' , '2018-01-01' , '女');

SELECT *, TIMESTAMPDIFF(YEAR,Sage,NOW())AS age
FROM Student;