ListItem[] schlist = new ListItem[db.GetTable<schInfo>().Count()];
        for (int i = 0; i < schlist.Length; i++)
        {
            foreach (var s in db.GetTable<schInfo>())
            {
                schlist[i].Text = s.schCode + "  " + s.schName;
                schlist[i].Value = s.schCode;
            }
            schCode.Items.Add(schlist[i]);
        }
        DataBind();