Mysql那些事儿之(五)操作时间_MySQL-Mysql Tutorial-php.cn

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Mysql那些事儿之(五)操作时间_MySQL

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Jun 01, 2016 pm 01:39 PM

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Mysql那些事儿之(五)操作时间一、时间命令：SELECT CURDATE(); 功能：以‘YYYY-MM-DD’的格式返回今天日期值。命令：SELECT CURTIME(); 功能：以‘HH:MM:SS’的格式返回时间。命令：SELECT NOW(); 功能：以‘YYYY-MM-DD HH:MM:SS’的格式返回时间。二、自动记录时间 TIMESTAMP 列类型可以自动的标记 INSERT UPDATE的操作的时间。举例：创建表 CREATE TABLE student（ id INT, english TINYINT, math TINYINT, chinese TINYINT, time TIMESTAMP ）；插入数据： INSERT INTO student(id,english,math,chinese) VALUES(1,12,23,45); 查询数据： SELECT * FROM student; 结果： --------------------------------------------------------------------- id | english | math | chinese | time | --------------------------------------------------------------------- 1 | 12 | 23 | 45 | 2012-10-20 10:34:09 --------------------------------------------------------------------- time列自动加入了数据INSERT 的时间。UPDATE 同样会影响数据的time列的时间值。 TIMESTAMP 的存储需求是4个字节；DATETIME存储需求是8个字节。三、比较时间 SELECT TO_DAYS(date); 给出一个日期date，返回从0年开始算的天数（到date为止）。举例： SELECT TO_DAYS(NOW())-TO_DAYS('2012-10-19'): 返回 1 天。 SELECT TO_DAYS(NOW()); 返回 735161 天。即从现在到0年为止的天数。 bitsCN.com

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