Oracle SQL 按字符串聚合字段分组

Question

我在对查询中的字段进行分组时遇到问题。这是我正在谈论的示例：

示例：

AIR_DT             DOL_GAP_TIME         MATL_SIZE                     
15-JAN-15          8:00 AM              30
15-JAN-15          8:00 AM              25
15-JAN-15          9:00 AM              5
15-JAN-15          9:00 AM              10
15-JAN-15          9:00 AM              5
15-JAN-15          9:00 AM              20

相同时间的归为一组，汇总matl_size

预期输出：

AIR_DT             DOL_GAP_TIME         MATL_SIZE                     
15-JAN-15          8:00 AM              55
15-JAN-15          9:00 AM              40

这是我的 SQL:

SELECT 
      a.air_dt, 
      TRIM(SUBSTR(TO_CHAR (a.dol_pref_start_time, 'mm/dd/yyyy hh:mi:ss AM'),12,2))
      || ':00 '
      || TRIM(SUBSTR (TO_CHAR (a.dol_pref_start_time, 'mm/dd/yyyy hh:mi:ss    AM'),
21, 2)) dol_gap_time, e.matl_size
FROM order_implem_dtl_broadcast a, matl_mstr b, matl_size_mstr e 
WHERE a.matl_id = b.matl_id 
AND b.matl_size_id = e.matl_size_id  
AND a.air_dt LIKE '%15-JAN-15%'
GROUP BY a.air_dt, a.dol_pref_start_time, e.matl_size
ORDER BY a.air_dt, a.dol_pref_start_time;

感谢您的提前帮助！

Answer 1

根据您的示例数据，这应该可以满足您的要求：

select AIR_DT, DOL_GAP_TIME, sum(MATL_SIZE)
from table t
group by AIR_DT, DOL_GAP_TIME;

但是，我不知道这与问题中的查询有什么关系。

Answer 2

好的，让我们开始您的初始查询：

SELECT 
  a.air_dt, 
  TRIM(SUBSTR(TO_CHAR (a.dol_pref_start_time, 'mm/dd/yyyy hh:mi:ss AM'),12,2))
  || ':00 '
  || TRIM(SUBSTR (TO_CHAR (a.dol_pref_start_time, 'mm/dd/yyyy hh:mi:ss    AM'), 21, 2)) dol_gap_time, e.matl_size
  FROM order_implem_dtl_broadcast a, matl_mstr b, matl_size_mstr e 
 WHERE a.matl_id = b.matl_id 
   AND b.matl_size_id = e.matl_size_id  
   AND a.air_dt LIKE '%15-JAN-15%'
 GROUP BY a.air_dt, a.dol_pref_start_time, e.matl_size
 ORDER BY a.air_dt, a.dol_pref_start_time;

我发现了几个问题。第一，您按 e.matl_size 分组，即使那是您想要 SUM() 的列。您不希望它出现在 GROUP BY 中。其次，您从 dol_pref_start_time 获取时间的方式真的很奇怪。看起来你想向下舍入到小时，然后只得到小时加上它是 AM 还是 PM。所以这个：

TRIM(SUBSTR(TO_CHAR (a.dol_pref_start_time, 'mm/dd/yyyy hh:mi:ss AM'),12,2))
  || ':00 '
  || TRIM(SUBSTR (TO_CHAR (a.dol_pref_start_time, 'mm/dd/yyyy hh:mi:ss    AM'), 21, 2)) dol_gap_time

可以简单地是这样的：

TO_CHAR(TRUNC(a.dol_pref_start_time, 'HH'), 'HH:MI AM') AS dol_gap_time

第三，您的日期存储为日期吗？如果是，你为什么要这样做？

AND a.air_dt LIKE '%15-JAN-15%'

这样做会好得多:

AND TRUNC(a.air_dt) = date'2015-01-15'

或者，如果您在 a.air_dt 上有索引，则此：

AND a.air_dt >= date'2015-01-15'
AND a.air_dt < date'2015-01-16'

将所有这些放在一起，我们得到这样的结果（请注意，我还将您的联接转换为 ANSI SQL 联接）：

SELECT TRUNC(a.air_dt) AS air_dt
     , TO_CHAR(TRUNC(a.dol_pref_start_time, 'HH'), 'HH:MI AM') AS dol_gap_time
     , SUM(e.matl_size) AS matl_size
  FROM order_implem_dtl_broadcast a INNER JOIN matl_mstr b
    ON a.matl_id = b.matl_id
 INNER JOIN matl_size_mstr e 
    ON b.matl_size_id = e.matl_size_id
 WHERE a.air_dt >= date'2015-01-15'
   AND a.air_dt < date'2015-01-16'
 GROUP BY TRUNC(a.air_dt), TO_CHAR(TRUNC(a.dol_pref_start_time, 'HH'), 'HH:MI AM')
 ORDER BY air_dt, TO_DATE(dol_gap_time, 'HH:MI AM'); -- using aliases in the ORDER BY, converting dol_gap_time to DATE for sorting

Oracle SQL 按字符串聚合字段分组

Oracle SQL Group By a String Aggregated Field

sql

oracle

group-by

oracle11g

oracle-sqldeveloper