SQL获取日期范围内同一表中不同记录的若干项的总和（ORACLE）

我有一个模式如下。我想运行以下查询：

从可以指定的日期范围内获取所有资产、描述、总成本（来自资产表）、驱动因素、polclass、manager（来自资产规格）和（所有增量的总和）作为使用。例如，这里我们可以指定从2015年11月2日到2016年1月30日，我们应该得到增量的总和作为使用量，因此记录如下所示

ASSETNUM|LOCATION|DESCRIPTION|TOTALCOST|DRIVER|POLCLASS|MANAGER|USAGE
----------------------------------------------------------------------
12345   | HERE   | SEDAN     |30000    |JOHN  | SPORT  | JOE   | 828(300+78+450) 
99999   |  .     | ......................................... 



ASSET:

ASSETNUM | LOCATION | DESCRIPTION | TOTALCOST
---------------------------------------------
12345    | HERE     | SEDAN       |30000    
99999    | THERE    | SUV         |50000
.        | .        |.            |.


ASSETSPEC:

ASSETNUM | ASSETATTRID | ALNVALUE  
---------------------------------
12345    | DRIVER      | JOHN    
12345    | POLCALSS    | SPORT           
12345    | MANAGER     | JOE           
99999    | DRIVER      | Greg  
99999    | POLCLASS    | SPORT 
99999    | .           | . 

METERREADING:

ASSETNUM | DELTA       | Reading Date  
---------------------------------
12345    | 78          | 1/30/2016      
12345    | 450         | 12/9/2015   
12345    | 300         | 11/2/2015

我想一次又一次地加入表以获取驱动程序、管理器和polclass，但我不知道如何获取日期范围内的增量之和。我的查询是这样的

SELECT V.ASSETNUM,
  drivers.ALNVALUE AS Driver,
  manager.ALNVALUE AS Manager,
  V.DESCRIPTION    AS ASSET_DESC,
  V.LOCATION,
  MAXIMO.LOCATIONS.DESCRIPTION AS Location_description,
  V.TOTALCOST,
  polclass.ALNVALUE AS POLICY_CLASS,
FROM MAXIMO.ASSET V
INNER JOIN MAXIMO.ASSETSPEC drivers
ON V.ASSETNUM           = drivers.ASSETNUM
AND drivers.ASSETATTRID = 'DRIVER'
INNER JOIN MAXIMO.ASSETSPEC polclass
ON V.ASSETNUM            = polclass.ASSETNUM
AND polclass.ASSETATTRID = 'POLCLASS'
INNER JOIN MAXIMO.ASSETSPEC manager
ON V.ASSETNUM           = manager.ASSETNUM
AND manager.ASSETATTRID = 'MANAGER'
INNER JOIN MAXIMO.LOCATIONS
ON MAXIMO.LOCATIONS.LOCATION = V.LOCATION
INNER JOIN MAXIMO.METERREADING
ON MAXIMO.METERREADING.ASSETNUM = V.ASSETNUM

试试这个：

select assetnum,location,
    description,totalcost,
    manager,polcalss,driver,
    sum(delta) total_delta from
(select * from (
    select a.assetnum, 
    a.location, 
    a.description, 
    a.totalcost, 
    b.assetattrid, 
    b.alnvalue, 
    m.delta
from asset a inner join assetspec b on a.assetnum = b.assetnum
    inner join meterreading m on a.assetnum = m.assetnum
where m.reading_date between 
    to_date('1/30/2015','mm/dd/yyyy') 
    and to_date('1/30/2016','mm/dd/yyyy')
)
pivot
    (max(alnvalue) for 
    (assetattrid) in ('manager' as manager,
        'polcalss' as polcalss, 
        'driver' as driver))
)
group by assetnum,location,description,
totalcost,manager,polcalss,driver;

---

您可以

PIVOT

assetspec表以每个assetnum列的形式填充数据，而不必三次加入表fwiw。您将需要一个

SUM（）

aggregate查询来获得您所追求的总数。@Boneist谢谢。请提供您所引用的sql代码给我好吗？您可以找到一些有用的信息，您能解释一下为什么我们必须在那里使用max函数吗？谢谢。@jax仔细想想。对于给定的

assetnum

，manager可以有许多行，但输出中只有一个manager列。Pivot查询需要聚合函数根据这些行选择值。它可以是

COUNT

，

SUM

等。