/// <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.NestedParameter"/>.
        /// </returns>
        public virtual CDP4Common.DTO.NestedParameter MapToDto(NpgsqlDataReader reader)
        {
            string tempActualValue;
            string tempFormula;
            string tempIsVolatile;
            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.NestedParameter(iid, revisionNumber);

            dto.ActualState         = reader["ActualState"] is DBNull ? (Guid?)null : Guid.Parse(reader["ActualState"].ToString());
            dto.AssociatedParameter = Guid.Parse(reader["AssociatedParameter"].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("ActualValue", out tempActualValue))
            {
                dto.ActualValue = tempActualValue.UnEscape();
            }

            if (valueDict.TryGetValue("Formula", out tempFormula))
            {
                dto.Formula = tempFormula.UnEscape();
            }

            if (valueDict.TryGetValue("IsVolatile", out tempIsVolatile))
            {
                dto.IsVolatile = bool.Parse(tempIsVolatile);
            }

            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="nestedParameter">
        /// The NestedParameter 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.NestedParameter nestedParameter, CDP4Common.DTO.Thing container = null)
        {
            bool isHandled;
            var  valueTypeDictionaryAdditions = new Dictionary <string, string>();
            var  beforeUpdate = this.BeforeUpdate(transaction, partition, nestedParameter, container, out isHandled, valueTypeDictionaryAdditions);

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

                var valueTypeDictionaryContents = new Dictionary <string, string>
                {
                    { "ActualValue", !this.IsDerived(nestedParameter, "ActualValue") ? nestedParameter.ActualValue.Escape() : string.Empty },
                    { "Formula", !this.IsDerived(nestedParameter, "Formula") ? nestedParameter.Formula.Escape() : string.Empty },
                    { "IsVolatile", !this.IsDerived(nestedParameter, "IsVolatile") ? nestedParameter.IsVolatile.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}\".\"NestedParameter\"", partition);
                    sqlBuilder.AppendFormat(" SET (\"ValueTypeDictionary\", \"Container\", \"ActualState\", \"AssociatedParameter\", \"Owner\")");
                    sqlBuilder.AppendFormat(" = (:valueTypeDictionary, :container, :actualState, :associatedParameter, :owner)");
                    sqlBuilder.AppendFormat(" WHERE \"Iid\" = :iid;");

                    command.Parameters.Add("iid", NpgsqlDbType.Uuid).Value = nestedParameter.Iid;
                    command.Parameters.Add("valueTypeDictionary", NpgsqlDbType.Hstore).Value = valueTypeDictionaryContents;
                    command.Parameters.Add("container", NpgsqlDbType.Uuid).Value             = container.Iid;
                    command.Parameters.Add("actualState", NpgsqlDbType.Uuid).Value           = !this.IsDerived(nestedParameter, "ActualState") ? Utils.NullableValue(nestedParameter.ActualState) : Utils.NullableValue(null);
                    command.Parameters.Add("associatedParameter", NpgsqlDbType.Uuid).Value   = !this.IsDerived(nestedParameter, "AssociatedParameter") ? nestedParameter.AssociatedParameter : Utils.NullableValue(null);
                    command.Parameters.Add("owner", NpgsqlDbType.Uuid).Value = !this.IsDerived(nestedParameter, "Owner") ? nestedParameter.Owner : Utils.NullableValue(null);

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

                    this.ExecuteAndLogCommand(command);
                }
            }

            return(this.AfterUpdate(beforeUpdate, transaction, partition, nestedParameter, container));
        }