id | photo title | created_date XEi43 | my family | 2009 08 04 dDls | friends group | 2009 08 05 32kJ | beautiful place | 2009 08 06 EOIk | working late | 2009 08 07
说我的身份是32kJ.如何获得下一行或前一个?
解决方法
这是我用来查找上一个/下一个记录.表中的任何列都可以用作排序列,并且不需要连接或讨厌的黑客:
下一条记录(日期大于当前记录):
SELECT id,title,MIN(created) AS created_date FROM photo WHERE created > (SELECT created FROM photo WHERE id = '32kJ') GROUP BY created ORDER BY created ASC LIMIT 1;
上一记录(日期小于当前记录):
SELECT id,MAX(created) AS created_date FROM photo WHERE created < (SELECT created FROM photo WHERE id = '32kJ') GROUP BY created ORDER BY created DESC LIMIT 1;
例:
CREATE TABLE `photo` ( `id` VARCHAR(5) NOT NULL,`title` VARCHAR(255) NOT NULL,`created` DATETIME NOT NULL,INDEX `created` (`created` ASC),PRIMARY KEY (`id`) ) ENGINE = InnoDB; INSERT INTO `photo` (`id`,`title`,`created`) VALUES ('XEi43','my family','2009-08-04'); INSERT INTO `photo` (`id`,`created`) VALUES ('dDls','friends group','2009-08-05'); INSERT INTO `photo` (`id`,`created`) VALUES ('32kJ','beautiful place','2009-08-06'); INSERT INTO `photo` (`id`,`created`) VALUES ('EOIk','working late','2009-08-07'); SELECT * FROM photo ORDER BY created; +-------+-----------------+---------------------+ | id | title | created | +-------+-----------------+---------------------+ | XEi43 | my family | 2009-08-04 00:00:00 | | dDls | friends group | 2009-08-05 00:00:00 | | 32kJ | beautiful place | 2009-08-06 00:00:00 | | EOIk | working late | 2009-08-07 00:00:00 | +-------+-----------------+---------------------+ SELECT id,MIN(created) AS next_date FROM photo WHERE created > (SELECT created FROM photo WHERE id = '32kJ') GROUP BY created ORDER BY created ASC LIMIT 1; +------+--------------+---------------------+ | id | title | next_date | +------+--------------+---------------------+ | EOIk | working late | 2009-08-07 00:00:00 | +------+--------------+---------------------+ SELECT id,MAX(created) AS prev_date FROM photo WHERE created < (SELECT created FROM photo WHERE id = '32kJ') GROUP BY created ORDER BY created DESC LIMIT 1; +------+---------------+---------------------+ | id | title | prev_date | +------+---------------+---------------------+ | dDls | friends group | 2009-08-05 00:00:00 | +------+---------------+---------------------+