dynamic 匿名对象

  detailList = conn.Query<dynamic>(sql3);

 foreach (var item in detailList)

var sql5 = $"UPDATE vtm_GpsInfo SET USEFLAG='0' WHERE GPSID={item.GPSID}";
conn.Execute(sql5);

imei1 = detailList[0].IMEI,
imei2 = detailList.Count > 1 ? detailList[1].IMEI : ""