item_cd order_month qty
A 2005/09 10
A 2005/08 5
A 2005/07 12
A 2005/06 10
B 2005/07 10
B 2005/03 12
C 2005/05 7
C 2005/03 2
C 2004/12 10
C 2004/10 15
结果如下:(最接近9月的3个月的记录)
A 2005/09 10
A 2005/08 5
A 2005/07 12
B 2005/07 10
B 2005/03 12
C 2005/05 7
C 2005/03 2
C 2004/12 10如何写这句SQL???
A 2005/09 10
A 2005/08 5
A 2005/07 12
A 2005/06 10
B 2005/07 10
B 2005/03 12
C 2005/05 7
C 2005/03 2
C 2004/12 10
C 2004/10 15
结果如下:(最接近9月的3个月的记录)
A 2005/09 10
A 2005/08 5
A 2005/07 12
B 2005/07 10
B 2005/03 12
C 2005/05 7
C 2005/03 2
C 2004/12 10如何写这句SQL???
where order_month in(
select top 3 order_month from tb
where item_cd=a.item_cd
and order_month<='2005/09'
order by order_month)
where order_month in(
select top 3 order_month from tb
where item_cd=a.item_cd
and order_month<='2005/09'
order by order_month desc)
select *
from tablename
where datediff(month,order_month,'2005-9-30')<=3