遇到朋友提问,如下:
SELECT * FROM ali_users WHERE DATEDIFF(CAST(CONCAT(DATE_FORMAT(NOW(),'%y'),DATE_FORMAT(birthday,'-%m-%d'))AS DATE),CAST(DATE_FORMAT(NOW(),'%y-%m-%d') AS DATE)) <=1
上面的可以找到今天或者明天过生日的
假设今天是12月31日,这时候来年的1月1日的就找不到了,怎么办?
1,准备测试数据,需要包含跨年的数据
1.1,准备测试数据的SQL
-
USE test;
-
DROP TABLE IF EXISTS ali_users;
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CREATE TABLE ali_users (username VARCHAR(10),birthday DATE NOT NULL,iphone VARCHAR(16));
-
INSERT INTO ali_users SELECT \'MaoYi\',\'1985-09-04\',\'13998786543\' UNION ALL
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SELECT \'LiuEr\',\'1985-08-30\',\'13998786543\' UNION ALL
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SELECT \'ZhangSan\',\'1981-01-01\',\'13998786543\' UNION ALL
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SELECT \'LiSi\',\'1983-01-02\',\'13998786543\' UNION ALL
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SELECT \'WangWu\',\'1984-11-01\',\'13998786543\' UNION ALL
-
SELECT \'ZhaoLiu\',\'1984-11-01\',\'13998786543\' UNION ALL
-
SELECT \'SongQi\',\'1986-08-31\',\'13998786543\' UNION ALL
-
SELECT \'HuangBa\',\'1989-09-01\',\'13998786543\' UNION ALL
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SELECT \'ZengJiu\',\'1989-09-02\',\'13998786543\' UNION ALL
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SELECT \'LuoShi\',\'1985-09-03\',\'13998786543\' UNION ALL
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SELECT \'Tom\',\'1995-09-05\',\'13998786543\' UNION ALL
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SELECT \'Licy\',\'1991-12-30\',\'13998286543\' UNION ALL
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SELECT \'Cari\',\'1992-12-31\',\'13998286543\' UNION ALL
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SELECT \'Mark\',\'1992-01-03\',\'13998286543\' UNION ALL
- SELECT \'Ruby\',\'1992-01-04\',\'13998286547\';
1.2,在数据库命令行执行SQL
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mysql> USE test;
-
DATABASE CHANGED
-
mysql> DROP TABLE IF EXISTS ali_users;
-
QUERY OK, 0 ROWS affected (0.00 sec)
-
-
mysql> CREATE TABLE ali_users (username VARCHAR(10),birthday DATE NOT NULL,iphone VARCHAR(16));
-
QUERY OK, 0 ROWS affected (0.01 sec)
-
-
mysql> INSERT INTO ali_users SELECT \'MaoYi\',\'1985-09-04\',\'13998786543\' UNION ALL
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-> SELECT \'LiuEr\',\'1985-08-30\',\'13998786543\' UNION ALL
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-> SELECT \'ZhangSan\',\'1981-01-01\',\'13998786543\' UNION ALL
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-> SELECT \'LiSi\',\'1983-01-02\',\'13998786543\' UNION ALL
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-> SELECT \'WangWu\',\'1984-11-01\',\'13998786543\' UNION ALL
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-> SELECT \'ZhaoLiu\',\'1984-11-01\',\'13998786543\' UNION ALL
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-> SELECT \'SongQi\',\'1986-08-31\',\'13998786543\' UNION ALL
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-> SELECT \'HuangBa\',\'1989-09-01\',\'13998786543\' UNION ALL
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-> SELECT \'ZengJiu\',\'1989-09-02\',\'13998786543\' UNION ALL
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-> SELECT \'LuoShi\',\'1985-09-03\',\'13998786543\' UNION ALL
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-> SELECT \'Tom\',\'1995-09-05\',\'13998786543\' UNION ALL
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-> SELECT \'Licy\',\'1991-12-30\',\'13998286543\' UNION ALL
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-> SELECT \'Cari\',\'1992-12-31\',\'13998286543\' UNION ALL
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-> SELECT \'Mark\',\'1992-01-03\',\'13998286543\' UNION ALL
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-> SELECT \'Ruby\',\'1992-01-04\',\'13998286547\';
-
QUERY OK, 15 ROWS affected (0.01 sec)
-
Records: 15 Duplicates: 0 WARNINGS: 0
-
-
mysql> SELECT * FROM ali_users;
-
+----------+------------+-------------+
-
| username | birthday | iphone |
-
+----------+------------+-------------+
-
| MaoYi | 1985-09-04 | 13998786543 |
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| LiuEr | 1985-08-30 | 13998786543 |
-
| ZhangSan | 1981-01-01 | 13998786543 |
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| LiSi | 1983-01-02 | 13998786543 |
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| WangWu | 1984-11-01 | 13998786543 |
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| ZhaoLiu | 1984-11-01 | 13998786543 |
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| SongQi | 1986-08-31 | 13998786543 |
-
| HuangBa | 1989-09-01 | 13998786543 |
-
| ZengJiu | 1989-09-02 | 13998786543 |
-
| LuoShi | 1985-09-03 | 13998786543 |
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| Tom | 1995-09-05 | 13998786543 |
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| Licy | 1991-12-30 | 13998286543 |
-
| Cari | 1992-12-31 | 13998286543 |
-
| Mark | 1992-01-03 | 13998286543 |
-
| Ruby | 1992-01-04 | 13998286547 |
-
+----------+------------+-------------+
-
15 ROWS IN SET (0.00 sec)
-
- mysql>
2,写出查询SQL
SELECT * FROM ali_users WHERE
/*不跨年的查询*/
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;
2,1,跨年问题分析
因为跨年的时候生日字段通常月份比较小是1月,所以如果利用DATEDIFF来判断要与月份比较大12月来比较得到相差天数在N天之内的话,就需要YEAR(NOW())+1,当年年份+1再加上月份才能与NOW()比较得出真实的相差天数。
打个比方,今天是2013年12月30日,要查询出来5天之内的过生日的同事,那么2014年1月1日2日3日的也在查询范围之内,这个时候就需要CONCAT(YEAR(NOW())+1,DATE_FORMAT(birthday,'-%m-%d')年份加1形成2014-01-01才能与今天的2013-12-30进行比较得出正确的相差天数。
2.2,5天之内的设定
N天之内,用 BETWEEN 0 AND N 来判断,如果是5天之内(包含今天)那么N值就是4,就是 BETWEEN 0 AND 4
3,验证数据
比如提醒最近5天之内(包括今日)过生日的同事,生日快乐。
3.1,查询的数据都在今年之内的,比如今天是8月30日,那么需要执行的SQL如下:
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;
查询的结果应该是从今天8月30日到9月3日之间过生日的同事,包括LiuEr,SongQi,HuangBa,ZengJiu,LuoShi;
执行如下所示,符合预期,如下所示:
-
mysql> 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
-
-> ;
-
+----------+------------+-------------+
-
| username | birthday | iphone |
-
+----------+------------+-------------+
-
| LiuEr | 1985-08-30 | 13998786543 |
-
| SongQi | 1986-08-31 | 13998786543 |
-
| HuangBa | 1989-09-01 | 13998786543 |
-
| ZengJiu | 1989-09-02 | 13998786543 |
-
| LuoShi | 1985-09-03 | 13998786543 |
-
+----------+------------+-------------+
-
5 ROWS IN SET (0.00 sec)
-
- mysql>
3.2,查询的生日有跨年的
比如今天是2013年12月30日,要查询5天之内过生日的同事,那么就有2013年的12月30日31日过生日的,也有2014年1月1日2日3日过生日的同事,因为今天是8月30日,所以要把Step#2中的SQL的NOW()改成'2013-12-30 00:10:10'来进行测试,SQL整理如下:
SELECT * FROM ali_users WHERE
DATEDIFF(CAST(CONCAT(YEAR('2013-12-30 00:10:10'),DATE_FORMAT(birthday,'-%m-%d'))AS DATE),CAST(DATE_FORMAT('2013-12-30 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('2013-12-30 00:10:10')+1,DATE_FORMAT(birthday,'-%m-%d'))AS DATE),CAST(DATE_FORMAT('2013-12-30 00:10:10','%y-%m-%d') AS DATE)) BETWEEN 0 AND 4;
查询的结果应该是从今天8月30日到9月3日之间过生日的同事,包括Licy,Cari,ZhangSan,LiSi,Mark。
执行结果如下所示,符合预期,如下所示:
-
mysql> SELECT * FROM ali_users WHERE
-
-> DATEDIFF(CAST(CONCAT(YEAR(\'2013-12-30 00:10:10\'),DATE_FORMAT(birthday,\'-%m-%d\'))AS DATE),CAST(DATE_FORMAT(\'2013-12-30 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(\'2013-12-30 00:10:10\')+1,DATE_FORMAT(birthday,\'-%m-%d\'))AS DATE),CAST(DATE_FORMAT(\'2013-12-30 00:10:10\',\'%y-%m-%d\') AS DATE)) BETWEEN 0 AND 4
-
-> ;
-
+----------+------------+-------------+
-
| username | birthday | iphone |
-
+----------+------------+-------------+
-
| ZhangSan | 1981-01-01 | 13998786543 |
-
| LiSi | 1983-01-02 | 13998786543 |
-
| Licy | 1991-12-30 | 13998286543 |
-
| Cari | 1992-12-31 | 13998286543 |
-
| Mark | 1992-01-03 | 13998286543 |
-
+----------+------------+-------------+
-
5 ROWS IN SET (0.00 sec)
-
- mysql>
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'
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,录入测试数据
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mysql> use test;
-
Reading table information for completion of table and column names
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You can turn off this feature to get a quicker startup with -A
-
-
Database changed
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mysql> INSERT INTO ali_users SELECT \'Jeff\',\'1980-02-29\',\'13998786549\' UNION ALL SELECT \'XiaoTeng\',\'1980-03-01\',\'13998786549\'
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-> UNION ALL SELECT \'HeSheng\',\'1980-03-02\',\'13998786549\'
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-> UNION ALL SELECT \'JingPan\',\'1980-03-03\',\'13998786549\'
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-> UNION ALL SELECT \'WuHong\',\'1986-03-04\',\'13998786549\';
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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
把Step#2中的SQL的NOW()改成'2014-02-28 00:10:10'来进行测试,确实没有包括2月29日生日的同事,如下所示:
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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*/
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-> 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
5.4.1 准备判断是否闰年的SQL
-
DELIMITER $$
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USE `test`$$
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DROP FUNCTION IF EXISTS `f_not_leap_year`$$
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CREATE FUNCTION `f_not_leap_year`(p_year BIGINT) RETURNS BOOLEAN
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BEGIN
-
/*是闰年则返回0(false),不是闰年则返回1(true)*/
-
DECLARE v_flag INT DEFAULT 0;
-
/*①、普通年能被4整除且不能被100整除的为闰年。(如2004年就是闰年,1901年不是闰年)*/
-
IF (p_year%4)=0 AND (p_year%100)>0 THEN
-
SET v_flag=0;
-
/*②、世纪年能被400整除的是闰年。(如2000年是闰年,1900年不是闰年) */
-
ELSEIF (p_year%400)=0 THEN
-
SET v_flag=0;
-
/*③、对于数值很大的年份,这年如果能整除3200,并且能整除172800则是闰年。如172800年是闰年,
-
86400年不是闰年(因为虽然能整除3200,但不能整除172800)(此按一回归年365天5h48\'45.5\'\'计算)。
-
*/
-
ELSEIF (p_year%3200)=0 AND (p_year%172800)=0 THEN
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SET v_flag=0;
-
ELSE
-
SET v_flag=1;
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END IF;
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RETURN v_flag;
-
END$$
- 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
把Step#2中的SQL的NOW()改成'2014-02-28 00:10:10'来进行测试,SQL如下所示:
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
);
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\')) AS DATE))
-
BETWEEN 0 AND 4
- );
执行SQL检验成果,如果当天是2004-02-28,看到已经有2月29日的生日的同事被记录进来了,其实包含了2月28日、2月29日、3月1日、3月2日、3月3日的生日的同事。
PS:因为2月29日在当年存在,所以算这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(\'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>
6,总结
这种类似的场景,涉及到查询多少天之内的数据,以及涉及到跨度范围比较大的查询(比如跨年或者跨部门,跨省、跨国、跨公司等等),都可以用这个思路来需求解决问题的方法。