public static object GetMaxId()
        {
            string sConn      = PlavyConfig.GetConnectionString("db");
            SqlDb  db         = new SQLiteDb(sConn);
            var    dbFactory  = db.DbBuilder.DbFactory;
            var    dbOperator = dbFactory.GetDbParamOperator();

            var dblist = db.ExecuteScalar("select max(id) from tb_certs");

            if (dblist == null)
            {
                return(-1);
            }
            return(dblist);
        }