public HttpResponseMessage SubmitEvaluation([FromBody] Evaluation eval)
 {
     try
     {
         EvaluationsEntity evalEntity = new EvaluationsEntity(eval.deviceID, eval.presentationId);
         evalEntity.rating    = eval.rating;
         evalEntity.speakerID = eval.speakerId;
         evalEntity.comment   = eval.comment;
         evalEntity.timestamp = DateTime.Now;
         client.InsertUserEval(evalEntity);
     }
     catch (AlreadyExistsException e)
     {
         return(new HttpResponseMessage(HttpStatusCode.Conflict));
     }
     return(new HttpResponseMessage(HttpStatusCode.OK));
 }
        public void InsertUserEval(EvaluationsEntity evalEntity)
        {
            // Create a retrieve operation that takes a customer entity.
            TableOperation retrieveOperation = TableOperation.Retrieve <DevicesEntity>(partitionKeyConst, evalEntity.deviceID.ToString() + evalEntity.presentationID);

            // Execute the retrieve operation.
            TableResult retrievedResult = table.Execute(retrieveOperation);

            if (retrievedResult.Result != null)
            {
                throw new AlreadyExistsException("Du har allerede afgivet evaluering af denne præsentation");
            }

            // Create the InsertOrReplace TableOperation.
            TableOperation insertOperation = TableOperation.Insert(evalEntity);

            // Execute the operation.
            table.Execute(insertOperation);

            Console.WriteLine("Entity was updated.");
        }