add methods in Repository an dModel for importing data

kontor-gin/internal/repository/comicwork.go

@@ -25,3 +25,26 @@ func (repository *ComicworkRepository) FindAll(context context.Context) ([]model
 
 	return comicworks, nil
 }
+
+func (repository *ComicworkRepository) Import(dtos models.ComicworkDTOList) {
+	slog.Info("ComicworkRepository#Import")
+	for index, dto := range dtos {
+		slog.Info("importing", "index", index, "profile", dto)
+		model := dto.ConvertDTOToModel()
+		existing_item := models.ComicWork{ID: dto.ID}
+		result_existing := repository.db.First(&existing_item)
+		if result_existing.Error != nil {
+			slog.Info("check existing id: not found - inserting")
+			result := repository.db.Create(&model)
+			if result.Error != nil {
+				slog.Info("error during import", "error", result.Error.Error())
+			}
+		} else {
+			slog.Info("check existing id: found - updating")
+			result := repository.db.Save(&model)
+			if result.Error != nil {
+				slog.Info("error during updating", "error", result.Error.Error())
+			}
+		}
+	}
+}