目前下面的语句是计算出单次合计，那么总合计怎么计算出来呢！请高人指点！
Select case v1.FTranType when 80 then u1.FAmount+u1.FTaxAmount else u1.FAmount end as 单次合计
from ICSale v1 INNER JOIN ICSaleEntry u1 ON v1.FInterID = u1.FInterID AND u1.FInterID <>0
INNER JOIN t_Organization t4 ON v1.FCustID = t4.FItemID AND t4.FItemID <>0
INNER JOIN t_ICItem t17 ON u1.FItemID = t17.FItemID AND t17.FItemID <>0
LEFT OUTER JOIN t_MeasureUnit t500 ON t17.FSaleUnitID = t500.FItemID AND t500.FItemID <>0
where
1=1 AND (ISNULL(t4.FNumber,'') = '03.03.01.01.001') AND (v1.FTranType=86 AND ((v1.FDate>='2014-09-01' AND v1.FDate<'2014-10-01')))
------解决方案--------------------
sum(case when then)