VB ACCESS库内有2个表：ins(进货表),xsd(出货表),两者都有共同的商品名称，现在主要想取出不同商品总的销售数及进货数，然后进行比较以确定库存不足。两个合并取到DATAGRID后，显示的数量都不准了，单独取都是准的。小弟刚接触这玩意儿，找过度娘可也没找着好的办法，求大侠们相救，谢谢。
Private Sub Form_Load()
  Adodc1.ConnectionString = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" & App.Path & "\db_zbjxc.mdb;Persist Security Info=False"
   = adCmdText
  Adodc1.RecordSource = "select  xsd.商品名称,sum(xsd.数量) as 销售总量,sum(xsd.金额) as 总金额,avG(xsd.单价)as 平均价格 ,SUM(ins.进货数量) as 总进货量 from xsd,ins  where xsd.商品名称=ins.商品名称 group by xsd.商品名称  "
  Adodc1.Refresh
  Set DataGrid1.DataSource = Adodc1
End Sub

你试看：
Private Sub Form_Activate()
   Adodc1.ConnectionString = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" & App.Path & "\db_zbjxc.mdb;Persist Security Info=False" '打开数据库
       = adCmdunknow                'SQL必须用此句，否则会显示FROM子句出错
      Adodc1.RecordSource = "select  xsd.商品名称,sum(xsd.数量) as 销售总量,sum(xsd.金额) as 总金额,avG(xsd.单价)as 平均价格 ,SUM(ins.进货数量) as 总进货量 from xsd,ins  where xsd.商品名称=ins.商品名称 group by xsd.商品名称  "
      Adodc1.Refresh
        Set DataGrid1.DataSource = Adodc1
End Sub