where 语句后面可以用 + - 吗？
大致如下结构：Select * from {Material_List} where StockQty + (子查询) + (子查询) + (子查询) - (子查询) <= QuantityAlert and (MaterialsClass = '外购件' or MaterialsClass = '标准件')
请问这样写是不是不正确？加上子查询就没结果了……研究半天了，还发现个问题，最后的or 一定要括弧括起来才生效居然！
实际查询语句如下：
Select * from {Material_List} where StockQty + (select sum(Quantity) from{Buy_List} where Material = {Material_List}.MaterialSpecification and Status <> '已请购') + (select sum(Quantity) from{Request_Orders} where Material = {Material_List}.MaterialSpecification and Status = '已请购') + (Select sum(Quantity) from {Purchase_Orders} where Material = {Material_List}.MaterialSpecification And IQCNumber In (Select IQCNumber from {IQC_List} where Status <> '已入库'or Status is NULL)) - (Select sum(Failure) from {Purchase_Orders} where Material = {Material_List}.MaterialSpecification And IQCNumber In (Select IQCNumber from {IQC_List} where Status <> '已入库'or Status is NULL)) <= QuantityAlert and (MaterialsClass = '外购件' or MaterialsClass = '标准件')
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Post By：2013/12/24 12:47:00 [只看该作者]
Post By：2013/12/24 13:07:00 [只看该作者]
弄了大半天 郁闷