public static async Task InsertAsync <T>(DbContext context, IList <T> entities, TableInfo tableInfo, Action <decimal> progress)
        {
            var sqlConnection = await OpenAndGetSqlConnectionAsync(context);

            var transaction = context.Database.CurrentTransaction;

            try
            {
                using (var sqlBulkCopy = GetSqlBulkCopy(sqlConnection, transaction, tableInfo.BulkConfig.SqlBulkCopyOptions))
                {
                    bool setColumnMapping = !tableInfo.HasOwnedTypes;
                    tableInfo.SetSqlBulkCopyConfig(sqlBulkCopy, entities, setColumnMapping, progress);
                    try
                    {
                        if (!tableInfo.HasOwnedTypes)
                        {
                            using (var reader = ObjectReaderEx.Create(entities, tableInfo.ShadowProperties, tableInfo.ConvertibleProperties, context, tableInfo.PropertyColumnNamesDict.Keys.ToArray()))
                            {
                                await sqlBulkCopy.WriteToServerAsync(reader).ConfigureAwait(false);
                            }
                        }
                        else
                        {
                            var dataTable = GetDataTable <T>(context, entities);
                            await sqlBulkCopy.WriteToServerAsync(dataTable);
                        }
                    }
                    catch (InvalidOperationException ex)
                    {
                        if (!ex.Message.Contains(ColumnMappingExceptionMessage))
                        {
                            throw;
                        }
                        await context.Database.ExecuteSqlCommandAsync(SqlQueryBuilder.CreateTableCopy(tableInfo.FullTableName, tableInfo.FullTempTableName, tableInfo));

                        if (!tableInfo.BulkConfig.UseTempDB)
                        {
                            await context.Database.ExecuteSqlCommandAsync(SqlQueryBuilder.DropTable(tableInfo.FullTempOutputTableName));
                        }
                    }
                }
            }
            finally
            {
                if (transaction == null)
                {
                    sqlConnection.Close();
                }
            }
        }
        //public static void Insert<T>(DbContext context, IList<T> entities, TableInfo tableInfo, Action<decimal> progress)
        //{
        //    var sqlConnection = OpenAndGetSqlConnection(context);
        //    var transaction = context.Database.CurrentTransaction;
        //    try
        //    {
        //        using (var sqlBulkCopy = GetSqlBulkCopy(sqlConnection, transaction, tableInfo.BulkConfig.KeepIdentity))
        //        {
        //            sqlBulkCopy.BulkCopyTimeout = 960;
        //            tableInfo.SetSqlBulkCopyConfig(sqlBulkCopy, entities, progress);
        //            using (var reader = ObjectReaderEx.Create(entities, tableInfo.ShadowProperties, context, tableInfo.PropertyColumnNamesDict.Keys.ToArray()))
        //            {
        //                sqlBulkCopy.WriteToServer(reader);
        //            }
        //        }
        //    }
        //    finally
        //    {
        //        if (transaction == null)
        //        {
        //            sqlConnection.Close();
        //        }
        //    }
        //}


        #region MainOps
        public static void Insert <T>(DbContext context, IList <T> entities, TableInfo tableInfo, Action <decimal> progress)
        {
            var sqlConnection = OpenAndGetSqlConnection(context);
            var transaction   = context.Database.CurrentTransaction;

            try
            {
                using (var sqlBulkCopy = GetSqlBulkCopy(sqlConnection, transaction, tableInfo.BulkConfig.SqlBulkCopyOptions))
                {
                    var setColumnMapping = !tableInfo.HasOwnedTypes;
                    tableInfo.SetSqlBulkCopyConfig(sqlBulkCopy, entities, setColumnMapping, progress);
                    try
                    {
                        if (!tableInfo.HasOwnedTypes)
                        {
                            using (var reader = ObjectReaderEx.Create(entities, tableInfo.ShadowProperties, tableInfo.ConvertibleProperties, context, tableInfo.PropertyColumnNamesDict.Keys.ToArray()))
                            {
                                sqlBulkCopy.WriteToServer(reader);
                            }
                        }
                        else // With OwnedTypes DataTable is used since library FastMember can not (https://github.com/mgravell/fast-member/issues/21)
                        {
                            var dataTable = GetDataTable(context, entities);
                            sqlBulkCopy.WriteToServer(dataTable);
                        }
                    }
                    catch (InvalidOperationException ex)
                    {
                        if (!ex.Message.Contains(ColumnMappingExceptionMessage))
                        {
                            throw;
                        }

                        context.Database.ExecuteSqlCommand(SqlQueryBuilder.CreateTableCopy(tableInfo.FullTableName, tableInfo.FullTempTableName, tableInfo)); // Exception specify missing db column: Invalid column name ''
                        if (!tableInfo.BulkConfig.UseTempDB)
                        {
                            context.Database.ExecuteSqlCommand(SqlQueryBuilder.DropTable(tableInfo.FullTempOutputTableName));
                        }
                    }
                }
            }
            finally
            {
                if (transaction == null)
                {
                    sqlConnection.Close();
                }
            }
        }