Get primary key value of entity

Hi,

       I use EntitySchemaQuery to get Entity, but I can't get primary key value of result entity. The exception said: not found "Id" (something likes this)

EntitySchemaQuery esqDetails = new EntitySchemaQuery(UserConnection.EntitySchemaManager, "UsrExportDetails");

            esqDetails.AddColumn("Id");

            esqDetails.AddColumn("UsrCodeLevel1");

            esqDetails.Filters.Add(esqDetails.CreateFilterWithParameters(FilterComparisonType.Equal, "UsrExport", id));

            var exportDetails = esqDetails.GetEntityCollection(UserConnection);

            

            foreach    (var details in exportDetails)

            {

                var refId = details.GetTypedColumnValue("Id");

                var qrCodeRefId = details.GetTypedColumnValue("UsrCodeLevel1Id");

                

                this.Push(refId, qrCodeRefId, name, address, tel, fax);

            }