49162
这个SQL如果出现求和的sum(a.SaleArea)出现0的话，会直接报错 这个SQL该怎么处理，实现出现0的时候显示空或者其他的东西
SELECT sum(b.Amount)*10000/sum(a.SaleArea) as TargetCost
FROM (SELECT ProductID,sum(SaleArea) as SaleArea from dbo.Product_Sale group by ProductID) a
left join (select PeriodID,ProductID,Amount,CostCode,MAX(SaveDate) as SaveDate FROM dbo.Product_Cost
group by PeriodID,ProductID,Amount,CostCode) b on a.ProductID = b.ProductID
left join dbo.Relation_Period c on b.PeriodID = c.C_PeriodID
left join dbo.DIM_Period d on c.PeriodID = d.PeriodID
where b.CostCode = 'A.09'
and a.ProductID IN ('${ProductID}')
