一SQL语句的头痛问题

select code,goods_name,sum(quantity) as zje from buy_goods_list group by code
如上语句在MySQL-Front里运行通过
可我放在软件里运行如下就会提示多步操作错误
 strSql = "select code,goods_name,sum(quantity) as zje from buy_goods_list group by code "
  Set rs = New ADODB.Recordset
  With rs
  .CursorLocation = adUseClient
  .CursorType = adOpenDynamic
  .Open strSql, conn, , , adCmdText
  End With
关键是在sum(quantity) as zje 这句，去掉又会运行正常，谢谢知道问题是出在哪？quantity字段为INT 我想得到相同CODE的数值总和，为什么会执行不了，大家帮我看看

"select `code`,goods_name,sum(quantity) as zje from buy_goods_list group by `code` "