mysql - MariaDB 顺序错误但在 MySQL 中正确

Question

我的本​​地服务器上有 MySQL:5.6.17，生产服务器上有 5.5.45-MariaDB-log。给予this fiddle ，结果集在本地服务器(以及 mysql 5.5 和 5.6)上正确排序，但在 mariadb 上的生产环境中没有正确排序 - 请参见下图。知道为什么吗？这是 mariadb 错误吗？

Answer 1

> SELECT NULLIF('2015-11-19 15:08:22', 0);
+----------------------------------+
| NULLIF('2015-11-19 15:08:22', 0) |
+----------------------------------+
| 2015-11-19 15:08:22              |
+----------------------------------+
1 row in set, 1 warning (0.00 sec)

> SHOW WARNINGS;
+---------+------+---------------------------------------------------------+
| Level   | Code | Message                                                 |
+---------+------+---------------------------------------------------------+
| Warning | 1292 | Truncated incorrect DOUBLE value: '2015-11-19 15:08:22' |
+---------+------+---------------------------------------------------------+
1 row in set (0.00 sec)

> SELECT NULLIF('2015-11-19 15:08:22', '0000-00-00 00:00:00');
+------------------------------------------------------+
| NULLIF('2015-11-19 15:08:22', '0000-00-00 00:00:00') |
+------------------------------------------------------+
| 2015-11-19 15:08:22                                  |
+------------------------------------------------------+
1 row in set (0.00 sec)

尝试:

SELECT
   e.id,
   e.dt_competition_last_manual_check,
   MAX(ec.dt_created) as m,
   # GREATEST always return NULL if present among arguments
   NULLIF(
      GREATEST(
         COALESCE(MAX(ec.dt_created), '0000-00-00 00:00:00'),
         COALESCE(e.dt_competition_last_manual_check, '0000-00-00 00:00:00')
      )
   , '0000-00-00 00:00:00') AS most_recent_dt_created_or_checked
FROM `estates` AS `e` 
   LEFT JOIN `estates` AS `ec` ON e.id = ec.estates_id_duplicate 
WHERE e.server = 'esk' 
GROUP BY `e`.`id` 
ORDER BY most_recent_dt_created_or_checked DESC;