asp select count(*) 用 open还是excute

  dSql1="select count(*) from test_hist where uid="&cid
  'dRs1.open dSql1,tConn,1,1
  'dSql1="select count(*) from test_hist where uid="&cid
  Set dRs1=tConn.Execute(dSql1)   如果去掉 Set 会报错
  testNum = dRs1(0)
  'testNum =0 
  IF IsNumeric(testNum) = False Then testNum = 0
  dRs1.close