cmd.CommandText = "select * from product where prod_code='" & Trim(txtprod_code.Text) & "' and branch='" & w_location & "' and avail_stock <>" & (0) & ""
cmd.CommandType = CommandType.Text
con.Open()
da_uqc.SelectCommand = cmd
cmd.Connection = con
da_uqc.Fill(ds_uqc)
m_qty = ds_uqc.Tables(0).Rows(0)(4) 'error 
da_uqc.Dispose()
ds_uqc.Dispose()
cmd.Dispose()

是否有可能像这样给出m_qty = ds_uqc.Tables(0).Rows(0)(4)？