private static TierPriceCollection DBMapping(DBTierPriceCollection dbCollection)
        {
            if (dbCollection == null)
                return null;

            TierPriceCollection collection = new TierPriceCollection();
            foreach (DBTierPrice dbItem in dbCollection)
            {
                TierPrice item = DBMapping(dbItem);
                collection.Add(item);
            }

            return collection;
        }
        /// <summary>
        /// Gets tier prices by product variant identifier
        /// </summary>
        /// <param name="ProductVariantID">Product variant identifier</param>
        /// <returns>Tier price collection</returns>
        public override DBTierPriceCollection GetTierPricesByProductVariantID(int ProductVariantID)
        {
            DBTierPriceCollection tierPriceCollection = new DBTierPriceCollection();
            Database db = NopSqlDataHelper.CreateConnection(_sqlConnectionString);
            DbCommand dbCommand = db.GetStoredProcCommand("Nop_TierPriceLoadAllByProductVariantID");
            db.AddInParameter(dbCommand, "ProductVariantID", DbType.Int32, ProductVariantID);
            using (IDataReader dataReader = db.ExecuteReader(dbCommand))
            {
                while (dataReader.Read())
                {
                    DBTierPrice tierPrice = GetTierPriceFromReader(dataReader);
                    tierPriceCollection.Add(tierPrice);
                }
            }

            return tierPriceCollection;
        }