SELECT 入库明细.物件编号, 入库明细.入库数量, 出库明细.出库数量, (Sum(入库明细.入库数量)-Sum(出库明细.出库数量)) AS 库存 FROM 出库明细 INNER JOIN 入库明细 ON 入库明细.物件编号=出库明细.物件编号 GROUP BY 入库明细.物件编号, 入库明细.入库数量, 出库明细.出库数量; 得到的库存1003万用表和1005没有,我要把他们也显示出来,问题在哪
SELECT 入库明细.物件编号, 入库明细.入库数量, isnull(出库明细.出库数量,0) as 出库数量, (Sum(入库明细.入库数量)-Sum(isnull(出库明细.出库数量,0))) AS 库存 FROM 出库明细 right JOIN 入库明细 ON 入库明细.物件编号=出库明细.物件编号 GROUP BY 入库明细.物件编号, 入库明细.入库数量, 出库明细.出库数量 ; 用left join 试试,isnull(出库明细.出库数量,0)解决 出库空数据null值加减运算问题