public function calculate_totals() {

		/**
		 * @var $wpdb wpdb
		 */
		global $wpdb;

		// Set totals.
		if ( false !== $this->total_sql ) {
			$total = @current( $wpdb->get_col( $this->get_sql( $this->total_sql ) ) );
		} else {
			$total = @current( $wpdb->get_col( 'SELECT FOUND_ROWS()' ) );
		}

		$total                        = self::do_hook( 'select_total', $total, $this );
		$this->total_found            = 0;
		$this->total_found_calculated = true;

		if ( is_numeric( $total ) ) {
			$this->total_found = $total;
		}
	}