在ms sql2000中用的case when 查询如果改为oracle该如何写?
在ms sql2000中用的case when:
select per_no 工号
,sum(case when per_no='01' then qty else 0 end) as per01qty
,sum(case when per_no='02' then qty else 0 end) as per02qty
from person m
group by m.per_no
查询如果改为oracle该如何写?