我有一个查询,需要计算一些列的一些计数和列的最大值的计数,然后按一些更多的标准进行分组。
到目前为止,我有以下查询:
select
subj.inventoryNum as Inventory,
extract(month from subj.createDate) as month,
oolame.schoolCode as Code,
count(case when max(subVers.verNum) > 0 then 1 end) as deleted,
count(case when subVers.delDate is not null then 1 end) as changed
from
Subjects subj
inner join SubjectVersions subVers on subVers.subjFk = subj.subjId
inner join SchoolName oolame on oolame.oolameId = subj.oolameFk
group by
subj.inventoryNum,
extract(month from subj.createDate),
oolame.schoolCode;
它给了我以下错误:
ORA-00937: not a single-group group function
00937. 00000 - "not a single-group group function"
*Cause:
*Action:
Error at Line: 2 Column: 1
你想做的事情有点不清楚。你想要总体最大值吗?每个科目的最大值?其他一些最大?
在任何情况下,您都可以在子查询中使用窗口函数来获得最大值。例如,如果您想要每个主题的最大值:
select subj.inventoryNum as Inventory,
extract(month from subj.createDate) as month,
oolame.schoolCode as Code,
sum(case when subVers.max_verNum > 0 then 1 else 0 end) as deleted,
count(subVers.delDate) as changed
from Subjects subj inner join
(select subvers.*,
max(subVers.verNum) over (partition by subVers.subjFk) as max_verNum
from SubjectVersions subVers
) subVers
on subVers.subjFk = subj.subjId inner join
SchoolName oolame
on oolame.oolameId = subj.oolameFk
group by subj.inventoryNum,
extract(month from subj.createDate),
oolame.schoolCode;