DB2 中联合查询的重复数据删除

Question

在联合中，我有来自两个可能相似的系统的记录，我不在乎来自哪个表，但我只需要保留一个并删除另一个。

这是表格的样子：

Select Agent, ID, System Name, APPID, Sum(Count) From Table 1
Union All Select Agent, ID, System Name, APPID, Sum(Count) From Table 2

Answer 1

UNION 而不是 UNION ALL 将完成这项工作

你也可以使用

with base as (
Select Agent, ID, System_Name, APPID, Sum(Count)  as count From Table 1
Union All Select Agent, ID, System_Name, APPID, Sum(Count) as count From Table 2
)
, temp as  (
select Agent, ID, System Name, APPID, count
       row_number() over (partition by Agent, ID, APPID) as rownum
from base
)
select Agent, ID, System Name, APPID, count
from temp
where rownum = 1 

由于目前缺少 iSeries，我尚未对其进行测试，但至少我希望这个想法应该清楚

补充：如果您需要有一定的排序偏好，您还可以在 PARTITON BY 之后添加 ORDER BY