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[MySQL]-->查询5天之内过生日的同事中的闰年2月29日问题的解决过程

2015-05-15 12:41 567 查看
前言:

上次写了查询5天之内过生日的同事中的跨年问题的解决过程,网址为:/article/1563966.html ,当中漏了一个闰年2月29日生日的细节问题,如今补充一下这个问题的处理过程:

5,补充闰年推断

有朋友提醒,闰年2月29日生日的话,可能查询不到,想到确实没有考虑到这个特殊的日期。
5.1,准备測试数据SQL,包括1980-02-29这一天生日的朋友。
INSERT INTO ali_users SELECT 'Jeff','1980-02-29','13998786549'
UNION ALL SELECT 'WeiYa','1980-02-28','13998786549'
UNION ALL SELECT 'XiaoTeng','1980-03-01','13998786549'
UNION ALL SELECT 'HeSheng','1980-03-02','13998786549'
UNION ALL SELECT 'JingPan','1980-03-03','13998786549'
UNION ALL SELECT 'WuHong','1986-03-04','13998786549';

5.2,录入測试数据
mysql> use test;

Reading table information for completion of table and column names

You can turn off this feature to get a quicker startup with -A

Database changed

mysql> INSERT INTO ali_users SELECT \'Jeff\',\'1980-02-29\',\'13998786549\' UNION ALL SELECT \'XiaoTeng\',\'1980-03-01\',\'13998786549\'

-> UNION ALL SELECT \'HeSheng\',\'1980-03-02\',\'13998786549\'

-> UNION ALL SELECT \'JingPan\',\'1980-03-03\',\'13998786549\'

-> UNION ALL SELECT \'WuHong\',\'1986-03-04\',\'13998786549\';

Query OK, 5 rows affected (0.00 sec)

Records: 5 Duplicates: 0 Warnings: 0

mysql>

5.3,运行原来的旧版本号的SQL查询检查结果

把Step#2中的SQL的NOW()改成'2014-02-28 00:10:10'来进行測试,确实没有包括2月29日生日的同事,例如以下所看到的:
mysql> SELECT * FROM ali_users WHERE

-> DATEDIFF(CAST(CONCAT(YEAR(\'2014-02-28 00:10:10\'),DATE_FORMAT(birthday,\'-%m-%d\'))AS DATE),CAST(DATE_FORMAT(\'2014-02-28 00:10:10\',\'%y-%m-%d\') AS DATE)) BETWEEN 0 AND 4

-> OR/* or后面的是捎带解决跨年问题*/

-> DATEDIFF(CAST(CONCAT(YEAR(\'2014-02-28 00:10:10\')+1,DATE_FORMAT(birthday,\'-%m-%d\'))AS DATE),CAST(DATE_FORMAT(\'2014-02-28 00:10:10\',\'%y-%m-%d\') AS DATE)) BETWEEN 0 AND 4

-> ;

+----------+------------+-------------+

| username | birthday | iphone |

+----------+------------+-------------+

| XiaoTeng | 1980-03-01 | 13998786549 |

| HeSheng | 1980-03-02 | 13998786549 |

| JingPan | 1980-03-03 | 13998786549 |

| WuHong | 1986-03-04 | 13998786549 |

+----------+------------+-------------+

4 rows in set, 2 warnings (0.00 sec)

mysql>

5.4,先建立一个存储函数f_isleap_year推断当年年份是否是闰年
5.4.1 准备推断是否闰年的SQL
DELIMITER $$

USE `test`$$

DROP FUNCTION IF EXISTS `f_not_leap_year`$$

CREATE FUNCTION `f_not_leap_year`(p_year BIGINT) RETURNS BOOLEAN

BEGIN

/*是闰年则返回0(false),不是闰年则返回1(true)*/

DECLARE v_flag INT DEFAULT 0;

/*①、普通年能被4整除且不能被100整除的为闰年。(如2004年就是闰年,1901年不是闰年)*/

IF (p_year%4)=0 AND (p_year%100)>0 THEN

SET v_flag=0;

/*②、世纪年能被400整除的是闰年。(如2000年是闰年,1900年不是闰年) */

ELSEIF (p_year%400)=0 THEN

SET v_flag=0;

/*③、对于数值非常大的年份,这年假设能整除3200,而且能整除172800则是闰年。如172800年是闰年,

86400年不是闰年(由于尽管能整除3200,但不能整除172800)(此按一回归年365天5h48\'45.5\'\'计算)。

*/

ELSEIF (p_year%3200)=0 AND (p_year%172800)=0 THEN

SET v_flag=0;

ELSE

SET v_flag=1;

END IF;

RETURN v_flag;

END$$

DELIMITER ;

存储函数运行例如以下图所看到的:



5.4.2 准备SQL语句

SELECT * FROM ali_users WHERE

DATEDIFF(CAST(CONCAT(YEAR(NOW()),DATE_FORMAT(birthday,\'-%m-%d\'))AS DATE),CAST(DATE_FORMAT(NOW(),\'%y-%m-%d\') AS DATE)) BETWEEN 0 AND 4

OR/* or后面的是捎带解决跨年问题*/

DATEDIFF(CAST(CONCAT(YEAR(NOW())+1,DATE_FORMAT(birthday,\'-%m-%d\'))AS DATE),CAST(DATE_FORMAT(NOW(),\'%y-%m-%d\') AS DATE)) BETWEEN 0 AND 4

OR /*补充闰年2月29日的生日问题*/

(

f_not_leap_year(YEAR(NOW()))

AND DATE_FORMAT(birthday,\'-%m-%d\')=\'-02-29\'

AND DATEDIFF(CAST(CONCAT(\'2000\',DATE_FORMAT(birthday,\'-%m-%d\'))AS DATE),CAST(CONCAT(\'2000\',DATE_FORMAT(NOW(),\'-%m-%d\')) AS DATE))

BETWEEN 0 AND 4

);

5.4.3 在非闰年的时候,验证闰年2月29日生日,选择2014年非闰年測试
把Step#2中的SQL的NOW()改成'2014-02-28 00:10:10'来进行測试,SQL例如以下所看到的:
SELECT * FROM ali_users WHERE
DATEDIFF(CAST(CONCAT(YEAR('2014-02-28 00:10:10'),DATE_FORMAT(birthday,'-%m-%d'))AS DATE),CAST(DATE_FORMAT('2014-02-28 00:10:10','%y-%m-%d') AS DATE)) BETWEEN 0 AND 4
OR/* or后面的是捎带解决跨年问题*/
DATEDIFF(CAST(CONCAT(YEAR('2014-02-28 00:10:10')+1,DATE_FORMAT(birthday,'-%m-%d'))AS DATE),CAST(DATE_FORMAT('2014-02-28 00:10:10','%y-%m-%d') AS DATE)) BETWEEN 0 AND 4
OR /*补充闰年2月29日的生日方法*/
(
f_not_leap_year(YEAR('2014-02-28 00:10:10'))
AND DATE_FORMAT(birthday,'-%m-%d')='-02-29'
AND DATEDIFF(CAST(CONCAT('2000',DATE_FORMAT(birthday,'-%m-%d'))AS DATE),CAST(CONCAT('2000',DATE_FORMAT('2000-02-28 00:10:10','-%m-%d')) AS DATE))
BETWEEN 0 AND 4
);

运行SQL检验成果,假设当天是2014-02-28,看到已经有2月29日的生日的同事被记录进来了,事实上包括了2月28日、2月29日、3月1日、3月2日、3月3日、3月4日的生日的同事。
PS:由于2月29日在当年不存在,所以不算这5天之内的范畴,运行结果例如以下所看到的:
mysql> SELECT * FROM ali_users WHERE

-> DATEDIFF(CAST(CONCAT(YEAR(\'2014-02-28 00:10:10\'),DATE_FORMAT(birthday,\'-%m-%d\'))AS DATE),CAST(DATE_FORMAT(\'2014-02-28 00:10:10\',\'%y-%m-%d\') AS DATE)) BETWEEN 0 AND 4

-> OR/* or后面的是捎带解决跨年问题*/

-> DATEDIFF(CAST(CONCAT(YEAR(\'2014-02-28 00:10:10\')+1,DATE_FORMAT(birthday,\'-%m-%d\'))AS DATE),CAST(DATE_FORMAT(\'2014-02-28 00:10:10\',\'%y-%m-%d\') AS DATE)) BETWEEN 0 AND 4

-> OR /*补充闰年2月29日的生日方法*/

-> (

-> f_not_leap_year(YEAR(\'2014-02-28 00:10:10\'))

-> AND DATE_FORMAT(birthday,\'-%m-%d\')=\'-02-29\'

-> AND DATEDIFF(CAST(CONCAT(\'2000\',DATE_FORMAT(birthday,\'-%m-%d\'))AS DATE),CAST(CONCAT(\'2000\',DATE_FORMAT(\'2000-02-28 00:10:10\',\'-%m-%d\')) AS DATE))

-> BETWEEN 0 AND 4

-> );

+----------+------------+-------------+

| username | birthday | iphone |

+----------+------------+-------------+

| Jeff | 1980-02-29 | 13998786549 |

| XiaoTeng | 1980-03-01 | 13998786549 |

| HeSheng | 1980-03-02 | 13998786549 |

| JingPan | 1980-03-03 | 13998786549 |

| WuHong | 1986-03-04 | 13998786549 |

| WeiYa | 1980-02-28 | 13998786549 |

+----------+------------+-------------+

6 rows in set, 2 warnings (0.00 sec)

mysql>

5.4.4 在闰年的时候,验证闰年2月29日生日,选择2004年闰年測试
把Step#2中的SQL的NOW()改成'2004-02-28 00:10:10'来进行測试,SQL例如以下所看到的:
SELECT * FROM ali_users WHERE

DATEDIFF(CAST(CONCAT(YEAR(\'2004-02-28 00:10:10\'),DATE_FORMAT(birthday,\'-%m-%d\'))AS DATE),CAST(DATE_FORMAT(\'2004-02-28 00:10:10\',\'%y-%m-%d\') AS DATE)) BETWEEN 0 AND 4

OR/* or后面的是捎带解决跨年问题*/

DATEDIFF(CAST(CONCAT(YEAR(\'2004-02-28 00:10:10\')+1,DATE_FORMAT(birthday,\'-%m-%d\'))AS DATE),CAST(DATE_FORMAT(\'2004-02-28 00:10:10\',\'%y-%m-%d\') AS DATE)) BETWEEN 0 AND 4

OR /*补充闰年2月29日的生日方法*/

(

f_not_leap_year(YEAR(\'2004-02-28 00:10:10\'))

AND DATE_FORMAT(birthday,\'-%m-%d\')=\'-02-29\'

AND DATEDIFF(CAST(CONCAT(\'2000\',DATE_FORMAT(birthday,\'-%m-%d\'))AS DATE),CAST(CONCAT(\'2000\',DATE_FORMAT(\'2004-02-28 00:10:10\',\'-%m-%d\')) ASDATE))

BETWEEN 0 AND 4

);

运行SQL检验成果,假设当天是2004-02-28,看到已经有2月29日的生日的同事被记录进来了,事实上包括了2月28日、2月29日、3月1日、3月2日、3月3日的生日的同事。
PS:由于2月29日在当年存在,所以算这5天之内的范畴,运行结果例如以下所看到的:

mysql> SELECT * FROM ali_users WHERE

-> DATEDIFF(CAST(CONCAT(YEAR(\'2004-02-28 00:10:10\'),DATE_FORMAT(birthday,\'-%m-%d\'))AS DATE),CAST(DATE_FORMAT(\'2004-02-28 00:10:10\',\'%y-%m-%d\') AS DATE)) BETWEEN 0 AND 4

-> OR/* or后面的是捎带解决跨年问题*/

-> DATEDIFF(CAST(CONCAT(YEAR(\'2004-02-28 00:10:10\')+1,DATE_FORMAT(birthday,\'-%m-%d\'))AS DATE),CAST(DATE_FORMAT(\'2004-02-28 00:10:10\',\'%y-%m-%d\') AS DATE)) BETWEEN 0 AND 4

-> OR /*补充闰年2月29日的生日方法*/

-> (

-> f_not_leap_year(YEAR(\'2004-02-28 00:10:10\'))

-> AND DATE_FORMAT(birthday,\'-%m-%d\')=\'-02-29\'

-> AND DATEDIFF(CAST(CONCAT(\'2000\',DATE_FORMAT(birthday,\'-%m-%d\'))AS DATE),CAST(CONCAT(\'2000\',DATE_FORMAT(\'2004-02-28 00:10:10\',\'-%m-%d\')) AS DATE))

-> BETWEEN 0 AND 4

-> );

+----------+------------+-------------+

| username | birthday | iphone |

+----------+------------+-------------+

| Jeff | 1980-02-29 | 13998786549 |

| XiaoTeng | 1980-03-01 | 13998786549 |

| HeSheng | 1980-03-02 | 13998786549 |

| JingPan | 1980-03-03 | 13998786549 |

| WeiYa | 1980-02-28 | 13998786549 |

+----------+------------+-------------+

5 rows in set (0.00 sec)

mysql>
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