Question

我需要编写基于AIRCRAFTREG列选择最早小时的查询。发现最早的一小时后，它会被标记为＆＃39; 1＆＃39;和另一个（非首飞）与＆＃39; 0＆＃39;在FIRST_FLIGHT列中。这是我的疑问：

select MIN(TO_CHAR(SCHEDULED_DEPDT_LC, 'DD-MM-YY HH24:MI')) SCHED_DEP,
       AIRCRAFTREG, 
       CASE WHEN MIN(TO_CHAR(SCHEDULED_DEPDT_LC, 'DD-MM-YY HH24:MI')) 
                 IN (TO_CHAR(SCHEDULED_DEPDT_LC, 'DD-MM-YYYY HH24:MI')) 
       THEN 1 ELSE 0 END FIRST_FLIGHT
from DBODSXML4OPS.XML4OPS
where STATUS IN ('Scheduled') 
  and SERVICETYPE IN ('J','G') 
  and ACTUAL_BLOCKOFF_LC is not null 
  and ACTUAL_BLOCKON_LC is not null 
  and (ACTUAL_BLOCKON_LC-SCHEDULED_ARRDT_LC)*24*60 > '+000000015 00:00:00.000000000' 
  and (ACTUAL_BLOCKOFF_LC-SCHEDULED_DEPDT_LC)*24*60 > '+000000015 00:00:00.000000000' 
  and TO_CHAR(SCHEDULED_DEPDT_LC, 'yyyy-mm-dd') BETWEEN '2018-05-02' and '2018-05-02'
group by AIRCRAFTREG, SCHEDULED_DEPDT_LC
order by AIRCRAFTREG;

结果：

+----------------+-------------+--------------+
|   SCHED_DEP    | AIRCRAFTREG | FIRST_FLIGHT |
+----------------+-------------+--------------+
| 02-05-18 14:25 | PK-GAA      |            0 |
| 02-05-18 16:55 | PK-GAI      |            0 |
| 02-05-18 12:50 | PK-GAJ      |            0 |
| 02-05-18 14:40 | PK-GAJ      |            0 |
| 02-05-18 16:05 | PK-GAJ      |            0 |
+----------------+-------------+--------------+

预期：

+----------------+-------------+--------------+
|   SCHED_DEP    | AIRCRAFTREG | FIRST_FLIGHT |
+----------------+-------------+--------------+
| 02-05-18 14:25 | PK-GAA      |            1 |
| 02-05-18 16:55 | PK-GAI      |            1 |
| 02-05-18 12:50 | PK-GAJ      |            1 |
| 02-05-18 14:40 | PK-GAJ      |            0 |
| 02-05-18 16:05 | PK-GAJ      |            0 |
+----------------+-------------+--------------+

Answer 1

我认为你需要一个analytic version of MIN函数而不是GROUP BY查询一个简单的例子（演示：http://sqlfiddle.com/#!4/bb331/3）

SELECT SCHED_DEP,
       AIRCRAFTREG,
       CASE WHEN SCHED_DEP =
            min( SCHED_DEP ) OVER (partition by AIRCRAFTREG )
       THEN 1 ELSE 0 END as FIRST_FLIGHT
FROM Table1
-- WHERE your where conditions are here
order by AIRCRAFTREG, SCHED_DEP

|             SCHED_DEP | AIRCRAFTREG | FIRST_FLIGHT |
|-----------------------|-------------|--------------|
| 2018-02-05 14:25:00.0 |      PK-GAA |            1 |
| 2018-02-05 16:55:00.0 |      PK-GAI |            1 |
| 2018-02-05 12:50:00.0 |      PK-GAJ |            1 |
| 2018-02-05 14:40:00.0 |      PK-GAJ |            0 |
| 2018-02-05 16:05:00.0 |      PK-GAJ |            0 |

Answer 2

首先你有一个拼写错误，你在选择中将YYYY char与YY进行比较。

其次我认为你需要在CASE语句中做一个子查询来找到aircraftreg代码的min（sched_dep）（它很难看，有更好的方法）。

按方法分组不允许您扫描所有其他行进行比较（只有同一行）。

根据Oracle中的特定参数查找最小值

2 个答案: