fix dapper select in

EVCB_OCPP.WSServer/Service/LoadingBalanceService.cs

@@ -284,14 +284,14 @@ namespace EVCB_OCPP.WSServer.Service
             {
                 string onlineChargerSql = "Select ChargeBoxId from [dbo].[Machine] where Id in @machineIds and [Online]=1; ";
                 var sqlParams = new DynamicParameters();
-                sqlParams.Add("@machineIds", machineIds, DbType.String, ParameterDirection.Input, 36);
+                sqlParams.Add("@machineIds", machineIds, size: 36);
                 var onlineResult = await conn.QueryAsync<string>(onlineChargerSql, sqlParams);
                 chargeboxids = onlineResult.ToList();
                 foreach (var chargeboxid in chargeboxids)
                 {
                     string txSql = "SELECT TOP(1) [Id] from [dbo].[TransactionRecord] where ChargeBoxId=@ChargeBoxId and StopTime = '1991-01-01 00:00:00.000'; ";
                     var param = new DynamicParameters();
-                    param.Add("ChargeBoxId", chargeboxid, DbType.String, ParameterDirection.Input, 50);
+                    param.Add("ChargeBoxId", chargeboxid, size: 50);
                     var txId = await conn.ExecuteScalarAsync<Int64>(txSql, param);
                     if (txId > 0)
                     {