protected function importBuildSqlQuery($table_name, $table_alias, $table_fields, $extra_where_clause = '', $is_override = false, $is_insert = true)
 {
     $proceed_with_query = true;
     if ($table_name == TABLE_PRODUCTS_ATTRIBUTES_DOWNLOAD) {
         if (empty($this->import_sql_data[TABLE_PRODUCTS_ATTRIBUTES_DOWNLOAD]['products_attributes_filename']['value'])) {
             $proceed_with_query = false;
         } elseif ($this->operation != 'check') {
             if ($this->import_is_insert) {
                 $this->import_sql_data[TABLE_PRODUCTS_ATTRIBUTES_DOWNLOAD]['products_attributes_id']['value'] = $this->key_fields['products_attributes_id'];
             } else {
                 $this->where_clause = "pad.products_attributes_id = " . $this->key_fields['products_attributes_id'];
             }
         }
     }
     return $proceed_with_query ? parent::importBuildSqlQuery($table_name, $table_alias, $table_fields, $extra_where_clause, $is_override, $is_insert) : false;
 }
 protected function importBuildSqlQuery($table_name, $table_alias, $table_fields, $extra_where_clause = '', $is_override = false, $is_insert = true)
 {
     return $table_name == TABLE_PRODUCTS ? false : parent::importBuildSqlQuery($table_name, $table_alias, $table_fields, $extra_where_clause, $is_override, $is_insert);
 }