如何按月计算净额

Question

SELECT EXTRACT(doc_date 的月份) columnno, sum(net_amt_rm) sum_amt, max(doc_date) ddate
来自POSM
WHERE EXTRACT（从 doc_date 开始的年份）= '2010'
GROUP BY EXTRACT（从 doc_date 开始的月份）

UNION //union no 2  
SELECT EXTRACT(month from doc_date) columnno, sum(net_amt_rm) sum_amt, max(doc_date) ddate  
FROM CIM  
WHERE EXTRACT(year from doc_date) = '2010'  
GROUP BY EXTRACT(month from doc_date)   

UNION  //union no3  
SELECT EXTRACT(month from doc_date) columnno, sum(net_amt_rm) sum_amt, max(doc_date) ddate  
FROM CAM  
WHERE EXTRACT(year from doc_date) = '2010'  
GROUP BY EXTRACT(month from doc_date)

这个查询的输出是这样的：

columnno | sum amt | ddate  
3             6      01/march/2010  
7            250     29/july/2010 // output for union no2  
7           2617     02/july/2010 // output for union no3

但我希望我的输出是这样的

columnno | sum amt | ddate  
3             6      march  
7            2867    july //output for union no 2 and 3 are sum together to get only one july

它的意思是仅一个月的总金额

Answer 1

试试这个

select columnno , sum(sum_amt), EXTRACT(month from ddate) ddate from 
<your query> 
group by columnno , (EXTRACT(month from ddate))