请问高手个子查询的问题?
现在有两个表,一个油品编码表PRODUCTTAB,用得着的就是两个字段PRODUCTID(油品编码),PRODUCTNAME(油品名称),一个油品入库表STOCKTAB,主要字段是PRODUCTID,STOCKTIME(入库时间),BILLNUMBER(提油单号),STOCKAMOUNT(入库数量),VAT(BIT类型字段)判断提油单是否结算,现在要查询的是某月前,没结算的提油单油品的总数量,某月内没结算的提油单油品的总数量,某月内和某月以前结算的提油单油品总数量,总数量都是分油品汇总,我的语句是,
SELECT PRODUCTNAME,LASTAMOUNT=(SELECT SUM(STOCKAMOUNT) FROM STOCKTAB S,PRODUCTTAB P WHERE S。PRODUCTID=P。PRODUCTID AND STOCKTIME<STARTTIME AND VAT=0 ),NOWAMOUNT=(SELECT SUM(STOCKAMOUNT) FROM STOCKTAB S,PRODUCTTAB P WHERE S。PRODUCTID=P。PRODUCTID AND STOCKTIME>STARTTIME AND
STOCKTIME<ENDTIME AND VAT=0),AMOUNT==(SELECT SUM(STOCKAMOUNT) FROM STOCKTAB S,PRODUCTTAB P WHERE S。PRODUCTID=P。PRODUCTID AND STOCKTIME<ENDTIME AND VAT=0) FROM Producttab group by PRODUCTNAME
大家帮我看一下问题出在那里