MariaDB 错误的顺序，但在 MySQL 中是正确的

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.给出

解决方案

>选择 NULLIF('2015-11-19 15:08:22', 0);+---------------------------------+|NULLIF('2015-11-19 15:08:22', 0) |+---------------------------------+|2015-11-19 15:08:22 |+---------------------------------+1 行，1 个警告(0.00 秒)>显示警告；+---------+------+---------------------------------------------------------------------+|水平 |代码 |留言 |+---------+------+---------------------------------------------------------------------+|警告 |第1292章截断不正确的 DOUBLE 值:'2015-11-19 15:08:22' |+---------+------+---------------------------------------------------------------------+一组中的 1 行(0.00 秒)>选择 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 |+-------------------------------------------------------+一组中的 1 行(0.00 秒)

试试:

SELECTe.id,e.dt_competition_last_manual_check,MAX(ec.dt_created) 作为 m，# 如果参数中存在，GREATEST 总是返回 NULLNULLIF(最棒的(COALESCE(MAX(ec.dt_created), '0000-00-00 00:00:00'),合并(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从`庄园`作为`e`LEFT JOIN `estates` AS `ec` ON e.id = ec.estates_id_duplicateWHERE e.server = 'esk'GROUP BY `e`.`id`ORDER BY most_recent_dt_created_or_checked DESC；

I have MySQL: 5.6.17 on my local server and 5.5.45-MariaDB-log on production server. Giving this fiddle, the resultset is correctly ordered on local server (mysql 5.5 and 5.6 as well), but not on production on mariadb - see image below.. any idea why? is this a mariadb bug?

解决方案

> 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)

Try:

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;