public bool CreateByKey(string key, Library.Types.ArticleRelationKeyType keyType)
        {
            try
            {
                switch (keyType)
                {
                    case Library.Types.ArticleRelationKeyType.SAN:
                        ArticleKeySAN articleKeySAN = new ArticleKeySAN(key);

                        if (articleKeySAN.IsValid())
                        {

                            ArticleRelation articleRelation = new ArticleRelation();
                            articleRelation.KeyValue = key;
                            articleRelation.Article = db.Articles.First(a => a.KeyValue == articleKeySAN.PlantNo);
                            if ((!string.IsNullOrEmpty(articleKeySAN.OptionModel1)) && (articleKeySAN.OptionModel1 != "0000"))
                            {
                                articleRelation.OptionModel1 = db.OptionModels.FirstOrDefault(a => (a.KeyValue == articleKeySAN.OptionModel1));
                                if (articleRelation.OptionModel1 == null)
                                    throw new Exception("OptionModel1 '" + articleKeySAN.OptionModel1 + "' not found in database");
                            }
                            if ((!string.IsNullOrEmpty(articleKeySAN.OptionModel2)) && (articleKeySAN.OptionModel2 != "0000"))
                            {
                                articleRelation.OptionModel2 = db.OptionModels.FirstOrDefault(a => (a.KeyValue == articleKeySAN.OptionModel2));
                                if (articleRelation.OptionModel2 == null)
                                    throw new Exception("OptionModel2 '" + articleKeySAN.OptionModel2 + "' not found in database");
                            }
                            if ((!string.IsNullOrEmpty(articleKeySAN.OptionModel3)) && (articleKeySAN.OptionModel3 != "0000"))
                            {
                                articleRelation.OptionModel3 = db.OptionModels.FirstOrDefault(a => (a.KeyValue == articleKeySAN.OptionModel3));
                                if (articleRelation.OptionModel3 == null)
                                    throw new Exception("OptionModel3 '" + articleKeySAN.OptionModel3 + "' not found in database");
                            }
                            articleRelation.SizeFrom = articleKeySAN.SizeFrom;
                            articleRelation.SizeTo = articleKeySAN.SizeTo;
                            if ((!string.IsNullOrEmpty(articleKeySAN.QualityLevel)) && (articleKeySAN.QualityLevel != "0000"))
                            {
                                articleRelation.QualityLevel = db.QualityLevels.FirstOrDefault(a => (a.KeyValue == articleKeySAN.QualityLevel));
                                if (articleRelation.QualityLevel == null)
                                    throw new Exception("QualityLevel '" + articleKeySAN.QualityLevel + "' not found in database");
                            }
                            if ((!string.IsNullOrEmpty(articleKeySAN.Forst1)) && (articleKeySAN.Forst1 != "00"))
                            {
                                articleRelation.Forst1 = db.Forsts.FirstOrDefault(a => (a.KeyValue == articleKeySAN.Forst1));
                                if (articleRelation.Forst1 == null)
                                    throw new Exception("Forst1 '" + articleKeySAN.Forst1 + "' not found in database");
                            }
                            if ((!string.IsNullOrEmpty(articleKeySAN.Forst2)) && (articleKeySAN.Forst2 != "00"))
                            {
                                articleRelation.Forst2 = db.Forsts.FirstOrDefault(a => (a.KeyValue == articleKeySAN.Forst2));
                                if (articleRelation.Forst2 == null)
                                    throw new Exception("Forst2 '" + articleKeySAN.Forst2 + "' not found in database");
                            }
                            if ((!string.IsNullOrEmpty(articleKeySAN.Bio)) && (articleKeySAN.Bio != "00"))
                            {
                                articleRelation.Bio = db.Bios.FirstOrDefault(a => (a.KeyValue == articleKeySAN.Bio));
                                if (articleRelation.Bio == null)
                                    throw new Exception("Bio '" + articleKeySAN.Bio + "' not found in database");
                            }

                            articleRelation.SourceType = SourceType.BdB_SAN;
                            articleRelation.KeyType = keyType;

                            return Create(articleRelation);
                        }
                        else
                        {
                            this._error = "Ungültige SAN Nummer: "+key;
                            return false;
                        }

                    default: return false;
                }

            }
            catch (Exception e)
            {
                this._error = e.Message;
                return false;
            }
        }