/// <summary>
        /// The mapping from a database record to data transfer object.
        /// </summary>
        /// <param name="reader">
        /// An instance of the SQL reader.
        /// </param>
        /// <returns>
        /// A deserialized instance of <see cref="CDP4Common.DTO.Approval"/>.
        /// </returns>
        public virtual CDP4Common.DTO.Approval MapToDto(NpgsqlDataReader reader)
        {
            string tempClassification;
            string tempContent;
            string tempCreatedOn;
            string tempLanguageCode;
            string tempModifiedOn;
            string tempThingPreference;

            var valueDict      = (Dictionary <string, string>)reader["ValueTypeSet"];
            var iid            = Guid.Parse(reader["Iid"].ToString());
            var revisionNumber = int.Parse(valueDict["RevisionNumber"]);

            var dto = new CDP4Common.DTO.Approval(iid, revisionNumber);

            dto.Author = Guid.Parse(reader["Author"].ToString());
            dto.ExcludedDomain.AddRange(Array.ConvertAll((string[])reader["ExcludedDomain"], Guid.Parse));
            dto.ExcludedPerson.AddRange(Array.ConvertAll((string[])reader["ExcludedPerson"], Guid.Parse));
            dto.Owner = Guid.Parse(reader["Owner"].ToString());

            if (valueDict.TryGetValue("Classification", out tempClassification))
            {
                dto.Classification = Utils.ParseEnum <CDP4Common.ReportingData.AnnotationApprovalKind>(tempClassification);
            }

            if (valueDict.TryGetValue("Content", out tempContent))
            {
                dto.Content = tempContent.UnEscape();
            }

            if (valueDict.TryGetValue("CreatedOn", out tempCreatedOn))
            {
                dto.CreatedOn = Utils.ParseUtcDate(tempCreatedOn);
            }

            if (valueDict.TryGetValue("LanguageCode", out tempLanguageCode))
            {
                dto.LanguageCode = tempLanguageCode.UnEscape();
            }

            if (valueDict.TryGetValue("ModifiedOn", out tempModifiedOn))
            {
                dto.ModifiedOn = Utils.ParseUtcDate(tempModifiedOn);
            }

            if (valueDict.TryGetValue("ThingPreference", out tempThingPreference) && tempThingPreference != null)
            {
                dto.ThingPreference = tempThingPreference.UnEscape();
            }

            return(dto);
        }
        /// <summary>
        /// Update a database record from the supplied data transfer object.
        /// </summary>
        /// <param name="transaction">
        /// The current <see cref="NpgsqlTransaction"/> to the database.
        /// </param>
        /// <param name="partition">
        /// The database partition (schema) where the requested resource will be updated.
        /// </param>
        /// <param name="approval">
        /// The Approval DTO that is to be updated.
        /// </param>
        /// <param name="container">
        /// The container of the DTO to be updated.
        /// </param>
        /// <returns>
        /// True if the concept was successfully updated.
        /// </returns>
        public virtual bool Update(NpgsqlTransaction transaction, string partition, CDP4Common.DTO.Approval approval, CDP4Common.DTO.Thing container = null)
        {
            bool isHandled;
            var  valueTypeDictionaryAdditions = new Dictionary <string, string>();
            var  beforeUpdate = this.BeforeUpdate(transaction, partition, approval, container, out isHandled, valueTypeDictionaryAdditions);

            if (!isHandled)
            {
                beforeUpdate = beforeUpdate && base.Update(transaction, partition, approval, container);

                var valueTypeDictionaryContents = new Dictionary <string, string>
                {
                    { "Classification", !this.IsDerived(approval, "Classification") ? approval.Classification.ToString() : string.Empty },
                }.Concat(valueTypeDictionaryAdditions).ToDictionary(kvp => kvp.Key, kvp => kvp.Value);

                using (var command = new NpgsqlCommand())
                {
                    var sqlBuilder = new System.Text.StringBuilder();
                    sqlBuilder.AppendFormat("UPDATE \"{0}\".\"Approval\"", partition);
                    sqlBuilder.AppendFormat(" SET (\"ValueTypeDictionary\", \"Container\", \"Author\", \"Owner\")");
                    sqlBuilder.AppendFormat(" = (:valueTypeDictionary, :container, :author, :owner)");
                    sqlBuilder.AppendFormat(" WHERE \"Iid\" = :iid;");

                    command.Parameters.Add("iid", NpgsqlDbType.Uuid).Value = approval.Iid;
                    command.Parameters.Add("valueTypeDictionary", NpgsqlDbType.Hstore).Value = valueTypeDictionaryContents;
                    command.Parameters.Add("container", NpgsqlDbType.Uuid).Value             = container.Iid;
                    command.Parameters.Add("author", NpgsqlDbType.Uuid).Value = !this.IsDerived(approval, "Author") ? approval.Author : Utils.NullableValue(null);
                    command.Parameters.Add("owner", NpgsqlDbType.Uuid).Value  = !this.IsDerived(approval, "Owner") ? approval.Owner : Utils.NullableValue(null);

                    command.CommandText = sqlBuilder.ToString();
                    command.Connection  = transaction.Connection;
                    command.Transaction = transaction;

                    this.ExecuteAndLogCommand(command);
                }
            }

            return(this.AfterUpdate(beforeUpdate, transaction, partition, approval, container));
        }
        /// <summary>
        /// Insert a new database record, or updates one if it already exists from the supplied data transfer object.
        /// This is typically used during the import of existing data to the Database.
        /// </summary>
        /// <param name="transaction">
        /// The current <see cref="NpgsqlTransaction"/> to the database.
        /// </param>
        /// <param name="partition">
        /// The database partition (schema) where the requested resource will be stored.
        /// </param>
        /// <param name="approval">
        /// The approval DTO that is to be persisted.
        /// </param>
        /// <param name="container">
        /// The container of the DTO to be persisted.
        /// </param>
        /// <returns>
        /// True if the concept was successfully persisted.
        /// </returns>
        public virtual bool Upsert(NpgsqlTransaction transaction, string partition, CDP4Common.DTO.Approval approval, CDP4Common.DTO.Thing container = null)
        {
            var valueTypeDictionaryAdditions = new Dictionary <string, string>();

            base.Upsert(transaction, partition, approval, container);

            var valueTypeDictionaryContents = new Dictionary <string, string>
            {
                { "Classification", !this.IsDerived(approval, "Classification") ? approval.Classification.ToString() : string.Empty },
            }.Concat(valueTypeDictionaryAdditions).ToDictionary(kvp => kvp.Key, kvp => kvp.Value);

            using (var command = new NpgsqlCommand())
            {
                var sqlBuilder = new System.Text.StringBuilder();

                sqlBuilder.AppendFormat("INSERT INTO \"{0}\".\"Approval\"", partition);
                sqlBuilder.AppendFormat(" (\"Iid\", \"ValueTypeDictionary\", \"Container\", \"Author\", \"Owner\")");
                sqlBuilder.AppendFormat(" VALUES (:iid, :valueTypeDictionary, :container, :author, :owner)");

                command.Parameters.Add("iid", NpgsqlDbType.Uuid).Value = approval.Iid;
                command.Parameters.Add("valueTypeDictionary", NpgsqlDbType.Hstore).Value = valueTypeDictionaryContents;
                command.Parameters.Add("container", NpgsqlDbType.Uuid).Value             = container.Iid;
                command.Parameters.Add("author", NpgsqlDbType.Uuid).Value = !this.IsDerived(approval, "Author") ? approval.Author : Utils.NullableValue(null);
                command.Parameters.Add("owner", NpgsqlDbType.Uuid).Value  = !this.IsDerived(approval, "Owner") ? approval.Owner : Utils.NullableValue(null);
                sqlBuilder.Append(" ON CONFLICT (\"Iid\")");
                sqlBuilder.Append(" DO UPDATE ");
                sqlBuilder.Append(" SET (\"ValueTypeDictionary\", \"Container\", \"Author\", \"Owner\")");
                sqlBuilder.Append(" = (:valueTypeDictionary, :container, :author, :owner);");

                command.CommandText = sqlBuilder.ToString();
                command.Connection  = transaction.Connection;
                command.Transaction = transaction;

                this.ExecuteAndLogCommand(command);
            }

            return(true);
        }