// JObject here is very very important...
        public ActionResult <string> Post([FromBody] JObject entityObj)
        {
            ORDER_DETAIL_MST postedEntity = entityObj.ToObject <ORDER_DETAIL_MST>();

            var orderListEntity = myContext.ORDER_LIST_MST.Where(d => d.ORDER_NO != null);

            if (!String.IsNullOrEmpty(postedEntity.ORDER_NO))
            {
                orderListEntity = orderListEntity.Where(d => d.ORDER_NO.Equals(postedEntity.ORDER_NO));
            }

            if (orderListEntity.Count() == 0)
            {
                // INSERT
                myContext.ORDER_LIST_MST.Add(postedEntity);
                myContext.SaveChanges();
                return("");
            }
            else
            {
                orderListEntity.First().CONTRACT_NO          = postedEntity.CONTRACT_NO;
                orderListEntity.First().PROJECT_NM           = postedEntity.PROJECT_NM;
                orderListEntity.First().ORDER_UNIT           = postedEntity.ORDER_UNIT;
                orderListEntity.First().SALES_PERSON         = postedEntity.SALES_PERSON;
                orderListEntity.First().DEPARTURE_DATE       = postedEntity.DEPARTURE_DATE.ToLocalTime();
                orderListEntity.First().DELIVERY_DATE        = postedEntity.DELIVERY_DATE.ToLocalTime();
                orderListEntity.First().REMARK               = postedEntity.REMARK;
                orderListEntity.First().APPLICATION_ENGINEER = postedEntity.APPLICATION_ENGINEER;
                myContext.SaveChanges();
                return("");
            }
        }
        public ActionResult <string> Delete(string ORDER_NO)
        {
            Boolean isSuccess = true;
            string  data      = "Delete success";

            if (!String.IsNullOrEmpty(ORDER_NO))
            {
                String[] ORDER_NO_LIST = ORDER_NO.Split(",");

                foreach (string ORDER_ITEM in ORDER_NO_LIST)
                {
                    ORDER_DETAIL_MST delMstEntity = new ORDER_DETAIL_MST()
                    {
                        ORDER_NO = ORDER_ITEM
                    };
                    if (delMstEntity.Equals(null))
                    {
                        isSuccess = false;
                        data      = "No such data.";
                        break;
                    }
                    else
                    {
                        // FIND ORDER DETAIL

                        /*
                         * int deteilNum = myContext.ORDER_LIST_DETAIL.Count(d => d.ORDER_NO == ORDER_ITEM);
                         * if (deteilNum > 0)
                         * {
                         *  isSuccess = false;
                         *  data = ORDER_ITEM + " has detail info.";
                         *  break;
                         * }
                         */
                        // FIND DB ITEM
                        myContext.ORDER_LIST_MST.Attach(delMstEntity);
                        // DELETE DB ITEM
                        myContext.ORDER_LIST_MST.Remove(delMstEntity);
                        // DELETE DETAIL ITEM
                        int deteilNum = myContext.ORDER_LIST_DETAIL.Count(d => d.ORDER_NO == ORDER_ITEM);
                        if (deteilNum > 0)
                        {
                            foreach (ORDER_LIST_DETAIL DetailEntity in myContext.ORDER_LIST_DETAIL.Where(d => d.ORDER_NO == ORDER_ITEM).ToList())
                            {
                                myContext.ORDER_LIST_DETAIL.Remove(DetailEntity);
                            }
                        }
                        // NEED TO CHECK DELETE RESULT HERE
                        if (true)
                        {
                            // SAVE CHANGES AND DO NOT RETURN
                            myContext.SaveChanges();
                        }
                        else
                        {
                            isSuccess = false;
                            data      = "No such data.";
                            break;
                        }
                    }
                }
            }
            else
            {
                isSuccess = false;
                data      = "No such data.";
            }
            JsonRes res = new JsonRes();

            res.isSuccess = isSuccess;
            res.data      = data;
            return(JsonConvert.SerializeObject(res));
        }