对 DB2 中的求和列应用列过滤器答案

【问题标题】：Apply column filter on summed columns in DB2对 DB2 中的求和列应用列过滤器
【发布时间】：2021-08-11 14:24:57
【问题描述】：

我有以下 DB2 表：

COLUMN_NAME	DATA_TYPE	TYPE_NAME	COLUMN_SIZE	COLUMN_TEXT
DMPROD	-2	CHAR () FOR BIT DATA	35	Product Code
DMPTYP	-2	CHAR () FOR BIT DATA	1	Period Type
DMTYPE	-2	CHAR () FOR BIT DATA	6	Type of Data
DMVL01	3	DECIMAL	17	Value Period 1
DMVL02	3	DECIMAL	17	Value Period 2
DMVL03	3	DECIMAL	17	Value Period 3
DMVL04	3	DECIMAL	17	Value Period 4
DMVL05	3	DECIMAL	17	Value Period 5
DMVL06	3	DECIMAL	17	Value Period 6
DMVL07	3	DECIMAL	17	Value Period 7
DMVL08	3	DECIMAL	17	Value Period 8
DMVL09	3	DECIMAL	17	Value Period 9
DMVL10	3	DECIMAL	17	Value Period 10
DMVL11	3	DECIMAL	17	Value Period 11
DMVL12	3	DECIMAL	17	Value Period 12
DMYEAR	3	DECIMAL	4	Fiscal Year

以下查询将返回每个 DMTYP 的值周期总和：

   SELECT
    D.DMPROD,
    Sum(CASE WHEN DMTYPE = 'SLSGSV' THEN D.DMVL01 + D.DMVL02 + D.DMVL03 + D.DMVL04 + D.DMVL05 + D.DMVL06 + D.DMVL07 + D.DMVL08 + D.DMVL09 + D.DMVL10 + D.DMVL11 + D.DMVL12 END) AS COST,    
    Sum(CASE WHEN DMTYPE = 'RTNCST' THEN D.DMVL01 + D.DMVL02 + D.DMVL03 + D.DMVL04 + D.DMVL05 + D.DMVL06 + D.DMVL07 + D.DMVL08 + D.DMVL09 + D.DMVL10 + D.DMVL11 + D.DMVL12 END) AS RTNCST,  
    Sum(CASE WHEN DMTYPE = 'RTNNET' THEN D.DMVL01 + D.DMVL02 + D.DMVL03 + D.DMVL04 + D.DMVL05 + D.DMVL06 + D.DMVL07 + D.DMVL08 + D.DMVL09 + D.DMVL10 + D.DMVL11 + D.DMVL12 END) AS RTNNET,  
    Sum(CASE WHEN DMTYPE = 'RTNQTY' THEN D.DMVL01 + D.DMVL02 + D.DMVL03 + D.DMVL04 + D.DMVL05 + D.DMVL06 + D.DMVL07 + D.DMVL08 + D.DMVL09 + D.DMVL10 + D.DMVL11 + D.DMVL12 END) AS RTNQTY,  
    Sum(CASE WHEN DMTYPE = 'RTNVAL' THEN D.DMVL01 + D.DMVL02 + D.DMVL03 + D.DMVL04 + D.DMVL05 + D.DMVL06 + D.DMVL07 + D.DMVL08 + D.DMVL09 + D.DMVL10 + D.DMVL11 + D.DMVL12 END) AS RTNVAL,
    Sum(CASE WHEN DMTYPE = 'SLSGSV' THEN D.DMVL01 + D.DMVL02 + D.DMVL03 + D.DMVL04 + D.DMVL05 + D.DMVL06 + D.DMVL07 + D.DMVL08 + D.DMVL09 + D.DMVL10 + D.DMVL11 + D.DMVL12 END) AS SLSGSV,
    Sum(CASE WHEN DMTYPE = 'SLSLST' THEN D.DMVL01 + D.DMVL02 + D.DMVL03 + D.DMVL04 + D.DMVL05 + D.DMVL06 + D.DMVL07 + D.DMVL08 + D.DMVL09 + D.DMVL10 + D.DMVL11 + D.DMVL12 END) AS SLSLST,
    Sum(CASE WHEN DMTYPE = 'SLSNIV' THEN D.DMVL01 + D.DMVL02 + D.DMVL03 + D.DMVL04 + D.DMVL05 + D.DMVL06 + D.DMVL07 + D.DMVL08 + D.DMVL09 + D.DMVL10 + D.DMVL11 + D.DMVL12 END) AS SLSNIV,
    Sum(CASE WHEN DMTYPE = 'SLSNTN' THEN D.DMVL01 + D.DMVL02 + D.DMVL03 + D.DMVL04 + D.DMVL05 + D.DMVL06 + D.DMVL07 + D.DMVL08 + D.DMVL09 + D.DMVL10 + D.DMVL11 + D.DMVL12 END) AS SLSNTN,
    Sum(CASE WHEN DMTYPE = 'SLSQTY' THEN D.DMVL01 + D.DMVL02 + D.DMVL03 + D.DMVL04 + D.DMVL05 + D.DMVL06 + D.DMVL07 + D.DMVL08 + D.DMVL09 + D.DMVL10 + D.DMVL11 + D.DMVL12 END) AS SLSQTY,
    Sum(CASE WHEN DMTYPE = 'XXD' THEN D.DMVL01 + D.DMVL02 + D.DMVL03 + D.DMVL04 + D.DMVL05 + D.DMVL06 + D.DMVL07 + D.DMVL08 + D.DMVL09 + D.DMVL10 + D.DMVL11 + D.DMVL12 END) AS XXD
FROM
    DWM D
WHERE
    D.DMYEAR IN (2022)
    AND D.DMPTYP = 'M'
GROUP BY
    D.DMPROD
ORDER BY
    1;

输出是我想要的，除了在不重写所有总和的情况下无法在此查询中轻松更改值周期。例如，假设我只想查看 DMYEAR 2022 中的价值期 1-5，我需要更改每个案例陈述。是否有更简单的方法（可能使用子查询）来保持 SUM 语句相同但仅选择最终输出所需的值周期？

【问题讨论】：

标签： sql db2 aggregates

【解决方案1】：

您可以使用子查询来解决这个问题：

SELECT
    D.DMPROD,
    Sum(CASE WHEN DMTYPE = 'SLSGSV' THEN val END) AS COST,    
    Sum(CASE WHEN DMTYPE = 'RTNCST' THEN val END) AS RTNCST,  
    Sum(CASE WHEN DMTYPE = 'RTNNET' THEN val END) AS RTNNET,  
    Sum(CASE WHEN DMTYPE = 'RTNQTY' THEN val END) AS RTNQTY,  
    Sum(CASE WHEN DMTYPE = 'RTNVAL' THEN val END) AS RTNVAL,
    Sum(CASE WHEN DMTYPE = 'SLSGSV' THEN val END) AS SLSGSV,
    Sum(CASE WHEN DMTYPE = 'SLSLST' THEN val END) AS SLSLST,
    Sum(CASE WHEN DMTYPE = 'SLSNIV' THEN val END) AS SLSNIV,
    Sum(CASE WHEN DMTYPE = 'SLSNTN' THEN val END) AS SLSNTN,
    Sum(CASE WHEN DMTYPE = 'SLSQTY' THEN val END) AS SLSQTY,
    Sum(CASE WHEN DMTYPE = 'XXD' THEN val END) AS XXD
FROM (SELECT D.*,
             (D.DMVL01 + D.DMVL02 + D.DMVL03 + D.DMVL04 + D.DMVL05) as val
      FROM DWM D
     ) D
WHERE D.DMYEAR IN (2022) AND D.DMPTYP = 'M'
GROUP BY D.DMPROD
ORDER BY 1;

【讨论】：

非常感谢，这正是我要找的

【解决方案2】：

我对你想要得到的东西做了一个尝试：

   SELECT 'SLSGSV' as DMTYPE,1 as DMVL01,2 as DMVL02,3 as DMVL03,4 as DMVL04,5 as DMVL05 INTO #temptable
   DECLARE @sumvariable INT

SELECT @sumvariable = SUM(D.DMVL01 + D.DMVL02 + D.DMVL03 + D.DMVL04 + D.DMVL05) 
FROM
    #temptable D
SELECT
        CASE WHEN DMTYPE = 'SLSGSV' THEN @sumvariable END AS COST,    
        CASE WHEN DMTYPE = 'RTNCST' THEN @sumvariable END AS RTNCST,  
        CASE WHEN DMTYPE = 'RTNNET' THEN @sumvariable END AS RTNNET,  
        CASE WHEN DMTYPE = 'RTNQTY' THEN @sumvariable END AS RTNQTY,  
        CASE WHEN DMTYPE = 'RTNVAL' THEN @sumvariable END AS RTNVAL,
        CASE WHEN DMTYPE = 'SLSGSV' THEN @sumvariable END AS SLSGSV,
        CASE WHEN DMTYPE = 'SLSLST' THEN @sumvariable END AS SLSLST,
        CASE WHEN DMTYPE = 'SLSNIV' THEN @sumvariable END AS SLSNIV,
        CASE WHEN DMTYPE = 'SLSNTN' THEN @sumvariable END AS SLSNTN,
        CASE WHEN DMTYPE = 'SLSQTY' THEN @sumvariable END AS SLSQTY,
        CASE WHEN DMTYPE = 'XXD' THEN @sumvariable END AS XXD
FROM #temptable

我的理解是您将根据年份需要设置变量。

【讨论】：