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：http://blog.csdn.net/mchdba/article/details/38952033 ，其中漏了一个闰年2月29日生日的细节问题，现在补充一下这个问题的处理过程：
5，补充闰年判断
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，准备测试数据SQL，包含1980-02-29这一天生日的朋友。
INSERT INTO ali_users SELECT 'Jeff','1980-02-29','13998786549'
5.2，录入测试数据
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，执行原来的旧版本的SQL查询检查结果
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判断当年年份是否是闰年
DELIMITER $$
USE `test`$$
DROP FUNCTION IF EXISTS `f_not_leap_year`$$
CREATE FUNCTION `f_not_leap_year`(p_year BIGINT) RETURNS BOOLEAN
BEGIN
/*是闰年则返回0(false)，不是闰年则返回1(true)*/
DECLARE v_flag INT DEFAULT 0;
/*①、普通年能被4整除且不能被100整除的为闰年。（如2004年就是闰年,1901年不是闰年）*/
IF (p_year%4)=0 AND (p_year%100)>0 THEN
SET v_flag=0;
/*②、世纪年能被400整除的是闰年。(如2000年是闰年，1900年不是闰年) */
ELSEIF (p_year%400)=0 THEN
SET v_flag=0;
/*③、对于数值很大的年份,这年如果能整除3200,并且能整除172800则是闰年。如172800年是闰年，
86400年不是闰年(因为虽然能整除3200，但不能整除172800)（此按一回归年365天5h48\'45.5\'\'计算）。
*/
ELSEIF (p_year%3200)=0 AND (p_year%172800)=0 THEN
SET v_flag=0;
ELSE
SET v_flag=1;
END IF;
RETURN v_flag;
END$$
DELIMITER ;
存储函数执行如下图所示：
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年非闰年测试
SELECT * FROM ali_users WHERE
执行SQL检验成果，如果当天是2014-02-28，看到已经有2月29日的生日的同事被记录进来了，其实包含了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：因为2月29日在当年不存在，所以不算这5天之内的范畴，执行结果如下所示：
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年闰年测试
把Step#2中的SQL的NOW()改成'2004-02-28 00:10:10'来进行测试，SQL如下所示：
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
);
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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